# import hashlib
# import json
# import os
# import shutil
# from datetime import date, datetime
# from os import path
#
# import core.utils
# import pytest
# from sdp.sheerkaDataProvider import SheerkaDataProvider, Event, SheerkaDataProviderError, \
#     SheerkaDataProviderDuplicateKeyError, SheerkaDataProviderResult, SheerkaDataProviderRef
# from sdp.sheerkaSerializer import JsonSerializer, Serializer, PickleSerializer
#
# tests_root = path.abspath("../../build/tests")
# evt_digest = "3a571cb6034ef6fc8d7fe91948d0d29728eed74de02bac7968b0e9facca2c2d7"
#
#
# def read_json_file(sdp, file_name):
#     with sdp.io.open(file_name, "r") as f:
#         return json.load(f)
#
#
# class ObjWithKey:
#     """
#     Object where the key can be resolved using get_key()
#     Not suitable for Json dump as there is no to_dict() method
#     """
#
#     def __init__(self, a, b):
#         self.a = a
#         self.b = b
#
#     def __eq__(self, obj):
#         return isinstance(obj, ObjWithKey) and \
#                self.a == obj.a and \
#                self.b == obj.b
#
#     def __repr__(self):
#         return f"ObjWithKey({self.a}, {self.b})"
#
#     def get_key(self):
#         return self.a
#
#
# class ObjSetKey:
#     """
#     Object where the key can be be automatically set thanks to set_key()
#     Not suitable for Json dump as there is no to_dict() method
#     """
#
#     def __init__(self, value, key=None):
#         self.value = value
#         self.key = key
#
#     def __eq__(self, obj):
#         return isinstance(obj, ObjSetKey) and \
#                self.key == obj.key and \
#                self.value == obj.value
#
#     def __repr__(self):
#         return f"ObjSetKey({self.key}, {self.value})"
#
#     def set_key(self, key):
#         self.key = key
#
#
# class ObjNoKey:
#     """
#     Object with no key, they won't be ordered
#     Not suitable for Json dump as there is no to_dict() method
#     """
#
#     def __init__(self, a, b):
#         self.a = a
#         self.b = b
#
#     def __hash__(self):
#         return hash((self.a, self.b))
#
#     def __eq__(self, obj):
#         return isinstance(obj, ObjNoKey) and \
#                self.a == obj.a and \
#                self.b == obj.b
#
#     def __repr__(self):
#         return f"ObjNoKey({self.a}, {self.b})"
#
#
# class ObjDumpJson:
#     """
#     Object where the key can be resolved using get_key()
#     that can be used to dump as Json
#     """
#
#     def __init__(self, key=None, value=None):
#         self.key = key
#         self.value = value
#
#     def __eq__(self, obj):
#         return isinstance(obj, ObjDumpJson) and \
#                self.key == obj.key and \
#                self.value == obj.value
#
#     def __repr__(self):
#         return f"ObjDumpJson({self.key}, {self.value})"
#
#     def get_key(self):
#         return self.key
#
#     def get_digest(self):
#         """
#         Returns the digest of the event
#         :return: hexa form of the sha256
#         """
#         return hashlib.sha256(f"Concept:{self.key}{self.value}".encode("utf-8")).hexdigest()
#
#     def to_dict(self):
#         return self.__dict__
#
#     def from_dict(self, as_dict):
#         self.value = as_dict["value"]
#         self.key = as_dict["key"]
#
#
# class ObjDumpJsonNoDigest:
#     """
#     Object where the key can be resolved using get_key()
#     that can be used to dump as Json,
#     But with no builtin digest computation
#     """
#
#     def __init__(self, key=None, value=None):
#         self.key = key
#         self.value = value
#
#     def __eq__(self, obj):
#         return isinstance(obj, ObjDumpJsonNoDigest) and \
#                self.key == obj.key and \
#                self.value == obj.value
#
#     def __repr__(self):
#         return f"ObjDumpJsonNoDigest({self.key}, {self.value})"
#
#     def get_key(self):
#         return self.key
#
#     def to_dict(self):
#         return self.__dict__
#
#     def from_dict(self, as_dict):
#         self.value = as_dict["value"]
#         self.key = as_dict["key"]
#
#
# class ObjWithDigestNoKey:
#     """
#     Object that can compute its digest.
#     It can be used to test objects sharing the same entry (but that are different)
#     Not suitable for Json dump as there is no to_dict() method
#     """
#
#     def __init__(self, a, b):
#         self.a = a
#         self.b = b
#
#     def __hash__(self):
#         return hash((self.a, self.b))
#
#     def __eq__(self, obj):
#         return isinstance(obj, ObjNoKey) and \
#                self.a == obj.a and \
#                self.b == obj.b
#
#     def __repr__(self):
#         return f"ObjWithDigestNoKey({self.a}, {self.b})"
#
#     def get_digest(self):
#         return str(self.a) + str(self.b)
#
#
# class ObjWithDigestWithKey:
#     """
#     Object with a key that can compute its digest.
#     It can be used to test objects sharing the same key (but that are different)
#     Not suitable for Json dump as there is no to_dict() method
#     """
#
#     def __init__(self, a, b):
#         self.a = a
#         self.b = b
#
#     def __hash__(self):
#         return hash((self.a, self.b))
#
#     def __eq__(self, obj):
#         return isinstance(obj, ObjWithDigestWithKey) and \
#                self.a == obj.a and \
#                self.b == obj.b
#
#     def __repr__(self):
#         return f"ObjWithDigestWithKey({self.a}, {self.b})"
#
#     def get_key(self):
#         return self.a
#
#     def get_digest(self):
#         return str(self.a) + str(self.b)
#
#
# @pytest.fixture(autouse=True)
# def init_test():
#     if path.exists(tests_root):
#         shutil.rmtree(tests_root)
#
#     if not path.exists(tests_root):
#         os.makedirs(tests_root)
#     current_pwd = os.getcwd()
#     os.chdir(tests_root)
#
#     yield None
#
#     os.chdir(current_pwd)
#
#
# @pytest.mark.parametrize("root, expected", [
#     (".sheerka", path.abspath(path.join(tests_root, ".sheerka"))),
#     ("mem://", "")
# ])
# def test_i_can_init_the_data_provider(root, expected):
#     sdp = SheerkaDataProvider(root)
#
#     assert sdp.io.root == expected
#     assert sdp.io.exists(sdp.io.root)
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_save_and_load_an_event(root):
#     sdp = SheerkaDataProvider(root)
#     event = Event("hello world", date=date(year=2007, month=9, day=10), user="kodjo")
#
#     evt_digest = sdp.save_event(event)
#     evt = sdp.load_event(evt_digest)
#
#     assert evt.version == 1
#     assert evt.date == datetime(year=2007, month=9, day=10)
#     assert evt.user_id == "kodjo"
#     assert evt.message == "hello world"
#     assert evt.parents is None
#     assert sdp.io.exists(path.join(sdp.io.root, SheerkaDataProvider.EventFolder, evt_digest[0:24], evt_digest))
#
#     # I can get the last event
#     evt = sdp.load_event()
#     assert evt.message == "hello world"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_get_event_history(root):
#     sdp = SheerkaDataProvider(root)
#     event = Event("hello world", date=date(year=2007, month=9, day=10), user="kodjo")
#     event2 = Event("hello world 2", date=date(year=2007, month=9, day=10), user="kodjo")
#
#     evt_digest1 = sdp.save_event(event)
#     evt_digest2 = sdp.save_event(event2)
#
#     evt = sdp.load_event(evt_digest2)
#     assert evt.version == 1
#     assert evt.date == datetime(year=2007, month=9, day=10)
#     assert evt.user_id == "kodjo"
#     assert evt.message == "hello world 2"
#     assert evt.parents == [evt_digest1]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_load_events(root):
#     sdp = SheerkaDataProvider(root)
#
#     for i in range(15):
#         sdp.save_event(Event(f"Hello {i}"))
#
#     events = list(sdp.load_events(10))  # first ten
#     assert len(events) == 10
#     assert events[0].message == "Hello 14"
#     assert events[9].message == "Hello 5"
#
#     events = list(sdp.load_events(10, 5))  # skip first 5, then take 10
#     assert len(events) == 10
#     assert events[0].message == "Hello 9"
#     assert events[9].message == "Hello 0"
#
#     events = list(sdp.load_events(20, 10))  # skip first 10, take 20,(but only 5 remaining)
#     assert len(events) == 5
#     assert events[0].message == "Hello 4"
#     assert events[4].message == "Hello 0"
#
#     events = list(sdp.load_events(1, 20))  # skip first 20, take one
#     assert len(events) == 0
#
#     events = list(sdp.load_events(0))  # all
#     assert len(events) == 15
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_load_events_when_no_event(root):
#     sdp = SheerkaDataProvider(root)
#
#     events = list(sdp.load_events(1))
#     assert len(events) == 0
#
#     events = list(sdp.load_events(1, 5))
#     assert len(events) == 0
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_an_string(root):
#     sdp = SheerkaDataProvider(root)
#     obj = "foo => bar"
#
#     result = sdp.add(evt_digest, "entry", obj)
#     last_commit = sdp.get_snapshot(SheerkaDataProvider.HeadFile)
#     state = sdp.load_state(last_commit)
#     loaded = sdp.get(result.entry, result.key)
#
#     assert result.obj == obj
#     assert result.entry == "entry"
#     assert result.key is None
#     assert result.digest is None
#     assert loaded == obj
#
#     assert sdp.io.exists(path.join(sdp.io.root, SheerkaDataProvider.StateFolder, last_commit[0:24], last_commit))
#     assert sdp.io.exists(path.join(sdp.io.root, SheerkaDataProvider.HeadFile))
#
#     assert state.date is not None
#     assert state.parents == []
#     assert state.events == [evt_digest]
#     assert state.data == {"entry": "foo => bar"}
#
#     assert sdp.io.read_text(path.join(sdp.io.root, SheerkaDataProvider.HeadFile)) == last_commit
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_several_strings_if_allow_multiple_is_true(root):
#     sdp = SheerkaDataProvider(root)
#
#     sdp.add(evt_digest, "entry", "foo")
#     sdp.add(evt_digest, "entry", "foo")
#     result = sdp.add(evt_digest, "entry", "bar")
#     loaded = sdp.get(result.entry, result.key)
#
#     assert result.obj == "bar"
#     assert result.entry == "entry"
#     assert result.key is None
#     assert result.digest is None
#     assert loaded == ["foo", "foo", "bar"]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_cannot_add_several_strings_if_allow_multiple_is_false(root):
#     sdp = SheerkaDataProvider(root)
#
#     with pytest.raises(IndexError) as index_error:
#         sdp.add(evt_digest, "entry", "foo", False)
#         sdp.add(evt_digest, "entry", "foo", False)
#     assert index_error.value.args[0] == "entry"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_an_object_with_no_key(root):
#     sdp = SheerkaDataProvider(root)
#     obj = ObjNoKey("a", "b")
#
#     result = sdp.add(evt_digest, "entry", obj)
#     last_commit = sdp.get_snapshot(SheerkaDataProvider.HeadFile)
#     state = sdp.load_state(last_commit)
#     loaded = sdp.get(result.entry, result.key)
#
#     assert result.obj == obj
#     assert result.entry == "entry"
#     assert result.key is None
#     assert result.digest is None
#
#     assert sdp.io.exists(path.join(sdp.io.root, SheerkaDataProvider.StateFolder, last_commit[0:24], last_commit))
#     assert sdp.io.exists(path.join(sdp.io.root, SheerkaDataProvider.HeadFile))
#
#     assert state.date is not None
#     assert state.parents == []
#     assert state.events == [evt_digest]
#     assert state.data == {"entry": ObjNoKey("a", "b")}
#
#     assert sdp.io.read_text(path.join(sdp.io.root, SheerkaDataProvider.HeadFile)) == last_commit
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_several_obj_no_key_if_allow_multiple_is_true(root):
#     sdp = SheerkaDataProvider(root)
#
#     sdp.add(evt_digest, "entry", ObjNoKey("a", "b"))
#     sdp.add(evt_digest, "entry", ObjNoKey("a", "b"))
#     result = sdp.add(evt_digest, "entry", ObjNoKey("c", "d"))
#     loaded = sdp.get(result.entry, result.key)
#
#     assert result.obj == ObjNoKey("c", "d")
#     assert result.entry == "entry"
#     assert result.key is None
#     assert result.digest is None
#     assert loaded == [ObjNoKey("a", "b"), ObjNoKey("a", "b"), ObjNoKey("c", "d")]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_cannot_add_several_obj_no_key_if_allow_multiple_is_false(root):
#     sdp = SheerkaDataProvider(root)
#
#     with pytest.raises(IndexError) as index_error:
#         sdp.add(evt_digest, "entry", ObjNoKey("a", "b"), False)
#         sdp.add(evt_digest, "entry", ObjNoKey("c", "d"), False)
#     assert index_error.value.args[0] == "entry"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_a_dict(root):
#     """
#     Adding a dictionary.
#     Note that there is no key when adding a dictionary
#
#     If you add {'my_key': 'my_value'}
#     'my_key is not considered as the key of the entry'
#
#     Because if you add {'my_key': 'my_value', 'my_key2': 'my_value2'}
#     There are now multiple keys.
#
#     So for dictionary entries, the key is not managed
#     """
#     sdp = SheerkaDataProvider(root)
#     obj = {"my_key": "my_value"}
#
#     result = sdp.add(evt_digest, "entry", obj)
#     last_commit = sdp.get_snapshot(SheerkaDataProvider.HeadFile)
#     state = sdp.load_state(last_commit)
#     loaded = sdp.get(result.entry, result.key)
#
#     loaded_value = sdp.get(result.entry, "my_key")  # we can retrieve by key
#
#     assert result.obj == obj
#     assert result.entry == "entry"
#     assert result.key is None  # we return None as dict may contains several entries
#     assert result.digest is None
#
#     assert loaded == obj
#     assert loaded_value == "my_value"
#
#     assert sdp.io.exists(path.join(sdp.io.root, SheerkaDataProvider.StateFolder, last_commit[0:24], last_commit))
#     assert sdp.io.exists(path.join(sdp.io.root, SheerkaDataProvider.HeadFile))
#
#     assert state.date is not None
#     assert state.parents == []
#     assert state.events == [evt_digest]
#     assert state.data == {"entry": obj}
#
#     assert sdp.io.read_text(path.join(sdp.io.root, SheerkaDataProvider.HeadFile)) == last_commit
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_multiple_entries_at_once_with_dict(root):
#     sdp = SheerkaDataProvider(root)
#     obj = {"my_key1": "value1", "my_key2": "value2"}
#
#     result = sdp.add(evt_digest, "entry", obj)
#     loaded = sdp.get(result.entry, result.key)
#     loaded_value1 = sdp.get(result.entry, "my_key1")
#     loaded_value2 = sdp.get(result.entry, "my_key2")
#
#     assert result.obj == obj
#     assert result.entry == "entry"
#     assert result.key is None  # we return None as dict may contains several entries
#     assert result.digest is None
#
#     assert loaded == {"my_key1": "value1", "my_key2": "value2"}
#     assert loaded_value1 == "value1"
#     assert loaded_value2 == "value2"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_same_key_with_dict_if_allow_multiple_is_true(root):
#     sdp = SheerkaDataProvider(root)
#
#     sdp.add(evt_digest, "entry", {"my_key": "my_value"})
#     result = sdp.add(evt_digest, "entry", {"my_key": "my_value"})
#     loaded1 = sdp.get(result.entry, result.key)
#
#     result = sdp.add(evt_digest, "entry", {"my_key": "my_value2"})
#     loaded2 = sdp.get(result.entry, result.key)
#
#     assert result.entry == "entry"
#     assert result.key is None
#     assert loaded1 == {"my_key": ["my_value", "my_value"]}
#     assert loaded2 == {"my_key": ["my_value", "my_value", "my_value2"]}
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_cannot_add_same_key_with_dict_if_allow_multiple_is_false(root):
#     sdp = SheerkaDataProvider(root)
#
#     with pytest.raises(IndexError) as index_error:
#         sdp.add(evt_digest, "entry", {"my_key": "my_value"}, False)
#         sdp.add(evt_digest, "entry", {"my_key": "my_value2"}, False)
#     assert index_error.value.args[0] == "entry.my_key"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_object_with_different_key_if_allow_multiple_is_false(root):
#     sdp = SheerkaDataProvider(root)
#
#     sdp.add(evt_digest, "entry", {"my_key": "a"}, False)
#     sdp.add(evt_digest, "entry", {"my_key2": "b"}, False)
#
#     assert sdp.get("entry", "my_key") == "a"
#     assert sdp.get("entry", "my_key2") == "b"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_obj_with_key(root):
#     sdp = SheerkaDataProvider(root)
#     obj1 = ObjWithKey("key1", "b")
#     obj2 = ObjSetKey("c", key="key2")
#
#     result1 = sdp.add(evt_digest, "entry", obj1)  # test when key is taken from obj.get_key()
#     result2 = sdp.add(evt_digest, "entry2", obj2)  # test when key is taken from obj.key
#     last_commit = sdp.get_snapshot(SheerkaDataProvider.HeadFile)
#     state = sdp.load_state(last_commit)
#
#     loaded1 = sdp.get(result1.entry, result1.key)
#     loaded2 = sdp.get(result2.entry, result2.key)
#
#     assert result1.obj == obj1
#     assert result1.entry == "entry"
#     assert result1.key == "key1"
#     assert result1.digest is None
#
#     assert result2.obj == obj2
#     assert result2.entry == "entry2"
#     assert result2.key == "key2"
#     assert result2.digest is None
#
#     assert loaded1 == ObjWithKey("key1", "b")
#     assert loaded2 == ObjSetKey("c", key="key2")
#
#     assert sdp.io.exists(path.join(sdp.io.root, SheerkaDataProvider.StateFolder, last_commit[0:24], last_commit))
#     assert sdp.io.exists(path.join(sdp.io.root, SheerkaDataProvider.HeadFile))
#
#     assert state.date is not None
#     assert len(state.parents) == 1
#     assert state.events == [evt_digest]
#     assert state.data == {"entry": {"key1": obj1}, "entry2": {"key2": obj2}}
#
#     assert sdp.io.read_text(path.join(sdp.io.root, SheerkaDataProvider.HeadFile)) == last_commit
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_objects_with_same_key_if_allow_multiple_is_true(root):
#     sdp = SheerkaDataProvider(root)
#
#     sdp.add(evt_digest, "entry", ObjWithKey("my_key", "b"))
#     result = sdp.add(evt_digest, "entry", ObjSetKey("c", key="my_key"))
#     loaded1 = sdp.get(result.entry, result.key)
#
#     result = sdp.add(evt_digest, "entry", ObjSetKey("c", key="my_key"))
#     sdp.add(evt_digest, "entry", ObjSetKey("c", key="my_key2"))  # to prove that it does not melt everything
#     loaded2 = sdp.get(result.entry, result.key)
#
#     assert loaded1 == [ObjWithKey("my_key", "b"), ObjSetKey("c", key="my_key")]
#     assert loaded2 == [ObjWithKey("my_key", "b"), ObjSetKey("c", key="my_key"), ObjSetKey("c", key="my_key")]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_cannot_add_object_with_same_key_if_allow_multiple_is_false(root):
#     sdp = SheerkaDataProvider(root)
#
#     with pytest.raises(IndexError) as index_error:
#         sdp.add(evt_digest, "entry", ObjWithKey("my_key", "b"), False)
#         sdp.add(evt_digest, "entry", ObjSetKey("c", key="my_key"), False)
#     assert index_error.value.args[0] == "entry.my_key"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_obj_with_key_to_a_list(root):
#     sdp = SheerkaDataProvider(root)
#
#     sdp.add(evt_digest, "entry", "foo")
#     sdp.add(evt_digest, "entry", "bar")  # entry is now a list
#     sdp.add(evt_digest, "entry", ObjWithKey("a", "b"))  # this entry must no be taken as a object with a key
#
#     loaded = sdp.get("entry")
#     assert loaded == ["foo", "bar", ObjWithKey("a", "b")]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_a_reference(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.serializer.register(PickleSerializer(lambda o: isinstance(o, ObjWithDigestWithKey)))
#     obj1 = ObjWithDigestWithKey(1, "foo")
#     result1 = sdp.add(evt_digest, "entry", obj1, use_ref=True)
#     result3 = sdp.add(evt_digest, "entry_by_ref", SheerkaDataProviderRef(obj1.b, obj1.get_digest()))
#
#     # another object
#     obj2 = ObjWithDigestWithKey(2, "bar")
#     sdp.add(evt_digest, "entry", obj2, use_ref=True)
#     sdp.add(evt_digest, "entry_by_ref", SheerkaDataProviderRef(obj2.b, obj2.get_digest()))
#
#     assert result1.obj == obj1
#     assert result1.entry == "entry"
#     assert result1.key == str(obj1.get_key())
#     assert result1.digest == obj1.get_digest()
#
#     assert result3.obj == SheerkaDataProviderRef(obj1.b, obj1.get_digest())
#     assert result3.entry == "entry_by_ref"
#     assert result3.key == "foo"
#     assert result3.digest is None
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {
#         "entry": {
#             "1": '##REF##:' + obj1.get_digest(),
#             "2": '##REF##:' + obj2.get_digest(),
#         },
#         "entry_by_ref": {
#             "foo": SheerkaDataProviderRef(obj1.b, obj1.get_digest()),
#             "bar": SheerkaDataProviderRef(obj2.b, obj2.get_digest())
#         },
#     }
#
#     # make sure that I can load back
#     loaded1 = sdp.get("entry_by_ref", "foo")
#     assert loaded1 == ObjWithDigestWithKey(1, "foo")
#     assert getattr(loaded1, Serializer.ORIGIN) == obj1.get_digest()
#
#     loaded2 = sdp.get("entry_by_ref", "bar")
#     assert loaded2 == ObjWithDigestWithKey(2, "bar")
#     assert getattr(loaded2, Serializer.ORIGIN) == obj2.get_digest()
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_have_multiple_is_ref_to_the_same_key(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.serializer.register(PickleSerializer(lambda o: isinstance(o, ObjWithDigestWithKey)))
#     ref_result1 = sdp.add(evt_digest, "entry", ObjWithDigestWithKey(1, "foo"), use_ref=True)
#     ref_result2 = sdp.add(evt_digest, "entry", ObjWithDigestWithKey(2, "bar"), use_ref=True)
#
#     sdp.add(evt_digest, "entry_ref", SheerkaDataProviderRef("1", ref_result1.digest))
#     sdp.add(evt_digest, "entry_ref", SheerkaDataProviderRef("1", ref_result2.digest))
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {'entry': {'1': '##REF##:1foo', '2': '##REF##:2bar'},
#                           'entry_ref': {'1': [SheerkaDataProviderRef("1", ref_result1.digest),
#                                               SheerkaDataProviderRef("1", ref_result2.digest)]},
#                           }
#
#     loaded = sdp.get("entry_ref", "1")
#     assert len(loaded) == 2
#     assert loaded[0] == ObjWithDigestWithKey(1, "foo")
#     assert loaded[1] == ObjWithDigestWithKey(2, "bar")
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_cannot_add_obj_with_no_key_when_then_entry_has_keys(root):
#     sdp = SheerkaDataProvider(root)
#
#     with pytest.raises(SheerkaDataProviderError) as error:
#         sdp.add(evt_digest, "entry", ObjWithKey("a", "b"))
#         sdp.add(evt_digest, "entry", "foo")
#
#     assert error.value.obj == "foo"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_string_using_auto_generated_key(root):
#     sdp = SheerkaDataProvider(root)
#     key_file = path.join(sdp.io.root, SheerkaDataProvider.KeysFile)
#
#     result1 = sdp.add_with_auto_key(evt_digest, "entry1", "foo")
#     result2 = sdp.add_with_auto_key(evt_digest, "entry1", "bar")
#     result3 = sdp.add_with_auto_key(evt_digest, "entry2", "baz")
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#
#     assert sdp.io.exists(key_file)
#     assert read_json_file(sdp, key_file) == {"entry1": 2, "entry2": 1}
#     assert state.data == {"entry1": {"1": "foo", "2": "bar"}, "entry2": {"1": "baz"}}
#     assert result1.obj == "foo"
#     assert result2.obj == "bar"
#     assert result3.obj == "baz"
#     assert result1.entry == "entry1"
#     assert result2.entry == "entry1"
#     assert result3.entry == "entry2"
#     assert result1.digest is None
#     assert result2.digest is None
#     assert result3.digest is None
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_cannot_add_the_same_digest_twice_in_the_same_entry(root):
#     """
#     If get_digest() is implemented, checks for duplicates
#     :return:
#     """
#     sdp = SheerkaDataProvider(root)
#
#     with pytest.raises(SheerkaDataProviderDuplicateKeyError) as error:
#         sdp.add(evt_digest, "entry", ObjWithDigestNoKey("a", "b"))
#         sdp.add(evt_digest, "entry", ObjWithDigestNoKey("a", "b"))
#
#     assert error.value.obj.get_digest() == ObjWithDigestNoKey("a", "b").get_digest()
#     assert error.value.key == "entry"
#     assert error.value.args[0] == "Duplicate object."
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_cannot_add_the_same_digest_twice_in_the_same_entry2(root):
#     """
#     If get_digest() is implemented, checks for duplicates in list when no key
#     :return:
#     """
#     sdp = SheerkaDataProvider(root)
#
#     with pytest.raises(SheerkaDataProviderDuplicateKeyError) as error:
#         sdp.add(evt_digest, "entry", ObjWithDigestNoKey("a", "b"))
#         sdp.add(evt_digest, "entry", ObjWithDigestNoKey("a", "c"))
#         sdp.add(evt_digest, "entry", ObjWithDigestNoKey("a", "b"))
#
#     assert error.value.obj.get_digest() == ObjWithDigestNoKey("a", "b").get_digest()
#     assert error.value.key == "entry"
#     assert error.value.args[0] == "Duplicate object."
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_cannot_add_the_same_digest_twice_in_the_same_entry3(root):
#     """
#     If get_digest() is implemented, checks for duplicates when the key is provided
#     :return:
#     """
#     sdp = SheerkaDataProvider(root)
#
#     with pytest.raises(SheerkaDataProviderDuplicateKeyError) as error:
#         sdp.add(evt_digest, "entry", ObjWithDigestWithKey("a", "b"))
#         sdp.add(evt_digest, "entry", ObjWithDigestWithKey("a", "b"))
#
#     assert error.value.obj.get_digest() == ObjWithDigestWithKey("a", "b").get_digest()
#     assert error.value.key == "entry.a"
#     assert error.value.args[0] == "Duplicate object."
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_cannot_add_the_same_digest_twice_in_the_same_entry4(root):
#     """
#     If get_digest() is implemented, checks for duplicates in list when the key is provided
#     :return:
#     """
#     sdp = SheerkaDataProvider(root)
#
#     with pytest.raises(SheerkaDataProviderDuplicateKeyError) as error:
#         sdp.add(evt_digest, "entry", ObjWithDigestWithKey("a", "b"))
#         sdp.add(evt_digest, "entry", ObjWithDigestWithKey("a", "c"))
#         sdp.add(evt_digest, "entry", ObjWithDigestWithKey("a", "b"))
#
#     assert error.value.obj.get_digest() == ObjWithDigestWithKey("a", "b").get_digest()
#     assert error.value.key == "entry.a"
#     assert error.value.args[0] == "Duplicate object."
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_get_and_set_key(root):
#     sdp = SheerkaDataProvider(root)
#     key_file = path.join(sdp.io.root, SheerkaDataProvider.KeysFile)
#     sdp.set_key("entry1", 1000)
#
#     sdp.get_next_key("entry1")
#     sdp.get_next_key("entry1")
#     sdp.get_next_key("entry1")
#     sdp.get_next_key("entry2")
#     sdp.get_next_key("entry2")
#
#     assert sdp.io.exists(key_file)
#     assert read_json_file(sdp, key_file) == {"entry1": 1003, "entry2": 2}
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_object_using_auto_generated_key(root):
#     sdp = SheerkaDataProvider(root)
#     key_file = path.join(sdp.io.root, SheerkaDataProvider.KeysFile)
#
#     result1 = sdp.add_with_auto_key(evt_digest, "entry1", ObjNoKey("a", "b"))
#     result2 = sdp.add_with_auto_key(evt_digest, "entry1", ObjNoKey("a", "b"))
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#
#     assert sdp.io.exists(key_file)
#     assert read_json_file(sdp, key_file) == {"entry1": 2}
#     assert state.data == {"entry1": {"1": ObjNoKey("a", "b"), "2": ObjNoKey("a", "b")}}
#
#     assert result1.obj == ObjNoKey("a", "b")
#     assert result2.obj == ObjNoKey("a", "b")
#     assert result1.entry == "entry1"
#     assert result2.entry == "entry1"
#     assert result1.key == "1"
#     assert result2.key == "2"
#     assert result1.digest is None
#     assert result2.digest is None
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_object_key_is_updated_when_possible_using_auto_generated_key(root):
#     sdp = SheerkaDataProvider(root)
#     key_file = path.join(sdp.io.root, SheerkaDataProvider.KeysFile)
#
#     result1 = sdp.add_with_auto_key(evt_digest, "entry1", ObjSetKey("foo"))
#     result2 = sdp.add_with_auto_key(evt_digest, "entry1", ObjSetKey("foo"))
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#
#     assert sdp.io.exists(key_file)
#     assert read_json_file(sdp, key_file) == {"entry1": 2}
#     assert state.data == {"entry1": {"1": ObjSetKey("foo", "1"), "2": ObjSetKey("foo", "2")}}
#
#     assert result1.obj == ObjSetKey("foo", "1")
#     assert result2.obj == ObjSetKey("foo", "2")
#     assert result1.entry == "entry1"
#     assert result2.entry == "entry1"
#     assert result1.key == "1"
#     assert result2.key == "2"
#     assert result1.digest is None
#     assert result2.digest is None
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_set_objects_with_key(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry", ObjWithKey(1, "foo"))
#     result = sdp.set(evt_digest, "entry", ObjWithKey(2, "foo"))
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {"entry": {"2": ObjWithKey(2, "foo")}}
#     assert result.entry == "entry"
#     assert result.key == "2"
#     assert result.digest is None
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_set_objects_with_no_key(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry", ObjNoKey(1, "foo"))
#     result = sdp.set(evt_digest, "entry", ObjNoKey(2, "foo"))
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {"entry": ObjNoKey(2, "foo")}
#     assert result.entry == "entry"
#     assert result.key is None
#     assert result.digest is None
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_set_from_list_to_dict(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.set(evt_digest, "entry", [ObjNoKey(1, "foo"), ObjNoKey(2, "foo")])
#     result = sdp.set(evt_digest, "entry", {"1": ObjNoKey(1, "foo"), "2": ObjNoKey(2, "foo")})
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {"entry": {"1": ObjNoKey(1, "foo"), "2": ObjNoKey(2, "foo")}}
#     assert result.entry == "entry"
#     assert result.key is None
#     assert result.digest is None
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_set_using_reference(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.serializer.register(PickleSerializer(lambda o: isinstance(o, ObjWithKey)))
#     sdp.add(evt_digest, "entry", ObjWithKey(1, "foo"))
#     result = sdp.set(evt_digest, "entry", ObjWithKey(2, "foo"), use_ref=True)
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {"entry": {"2": '##REF##:43f07065c7bad051cdd726bdfa4de7f8d754c31486c65ddb31d6b6548dec3db9'}}
#
#     assert result.obj == ObjWithKey(2, "foo")
#     assert result.entry == "entry"
#     assert result.key == "2"
#     assert result.digest == "43f07065c7bad051cdd726bdfa4de7f8d754c31486c65ddb31d6b6548dec3db9"
#
#     assert sdp.io.exists(sdp.io.get_obj_path(SheerkaDataProvider.ObjectsFolder,
#                                              "43f07065c7bad051cdd726bdfa4de7f8d754c31486c65ddb31d6b6548dec3db9"))
#
#     # sanity check, make sure that I can load back
#     loaded = sdp.get(result.entry, result.key)
#     assert loaded == ObjWithKey(2, "foo")
#     assert getattr(loaded, Serializer.ORIGIN) == "43f07065c7bad051cdd726bdfa4de7f8d754c31486c65ddb31d6b6548dec3db9"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_set_a_reference(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.serializer.register(PickleSerializer(lambda o: isinstance(o, ObjWithDigestWithKey)))
#     obj = ObjWithDigestWithKey(1, "foo")
#     sdp.add(evt_digest, "entry", obj, use_ref=True)
#     sdp.set(evt_digest, "entry_by_value", {obj.b: obj.get_digest()}, is_ref=True)
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {
#         "entry": {"1": '##REF##:' + obj.get_digest()},
#         "entry_by_value": {"foo": '##REF##:' + obj.get_digest()},
#     }
#
#     # sanity check, make sure that I can load back
#     loaded = sdp.get("entry_by_value", "foo")
#     assert loaded == ObjWithDigestWithKey(1, "foo")
#     assert getattr(loaded, Serializer.ORIGIN) == obj.get_digest()
#
#
# def test_i_cannot_set_using_use_ref_and_is_ref():
#     sdp = SheerkaDataProvider("mem://")
#
#     with pytest.raises(SheerkaDataProviderError):
#         sdp.set(evt_digest, "entry", ObjWithDigestWithKey("a", "b"), use_ref=True, is_ref=True)
#
#
# def test_i_cannot_set_using_is_ref_if_obj_is_not_a_dictionary():
#     sdp = SheerkaDataProvider("mem://")
#
#     with pytest.raises(SheerkaDataProviderError):
#         sdp.set(evt_digest, "entry", ObjWithDigestWithKey("a", "b"), is_ref=True)
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_an_object_with_a_key_as_a_reference(root):
#     sdp = SheerkaDataProvider(root)
#     obj = ObjDumpJson("my_key", "value1")
#     obj_serializer = JsonSerializer(core.utils.get_full_qualified_name(obj))
#     sdp.serializer.register(obj_serializer)
#
#     result = sdp.add(evt_digest, "entry", obj, use_ref=True)
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     digest = state.data["entry"]["my_key"][len(SheerkaDataProvider.REF_PREFIX):]
#
#     assert result.obj == obj
#     assert result.entry == "entry"
#     assert result.key == obj.key
#     assert result.digest == obj.get_digest()
#     assert digest == result.digest
#     assert state.data == {'entry': {'my_key': f"{SheerkaDataProvider.REF_PREFIX}{digest}"}}
#
#     loaded = sdp.load_obj(digest)
#     assert loaded == obj
#     assert getattr(loaded, Serializer.ORIGIN) == digest
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_a_dictionary_as_a_reference(root):
#     sdp = SheerkaDataProvider(root)
#     obj = {"my_key": "value1"}
#
#     # No need to register a serializer for dictionaries
#
#     result = sdp.add(evt_digest, "entry", obj, use_ref=True)
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     digest = state.data["entry"][len(SheerkaDataProvider.REF_PREFIX):]
#
#     assert result.obj == obj
#     assert result.entry == "entry"
#     assert result.key is None  # we return None as dict may contains several entries
#     assert result.digest == "1790cae3f354ecb6b419faaa2ee2c374ff33efb8cddafda9960924036ac04c1f"  # a digest is created
#     assert digest == result.digest
#
#     assert state.data == {'entry': f"{SheerkaDataProvider.REF_PREFIX}{digest}"}
#
#     loaded = sdp.load_obj(digest)
#     assert loaded["my_key"] == obj["my_key"]
#     assert loaded[Serializer.ORIGIN] == digest
#     assert len(loaded) == 2
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_an_object_with_no_builtin_digest_as_a_reference(root):
#     sdp = SheerkaDataProvider(root)
#     obj = ObjDumpJsonNoDigest("a", "b")
#
#     obj_serializer = JsonSerializer(core.utils.get_full_qualified_name(obj))
#     sdp.serializer.register(obj_serializer)
#
#     result = sdp.add(evt_digest, "entry", obj, use_ref=True)
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     digest = state.data["entry"][obj.get_key()][len(SheerkaDataProvider.REF_PREFIX):]
#
#     assert result.obj == obj
#     assert result.entry == "entry"
#     assert result.key == obj.get_key()
#     assert result.digest is not None
#     assert digest == result.digest
#
#     assert state.data == {'entry': {obj.key: f"{SheerkaDataProvider.REF_PREFIX}{result.digest}"}}
#
#     loaded = sdp.load_obj(digest)
#     assert getattr(loaded, Serializer.ORIGIN) == digest
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_unique(root):
#     sdp = SheerkaDataProvider(root)
#     result = sdp.add_unique(evt_digest, "entry", ObjNoKey(1, "foo"))
#     assert result == SheerkaDataProviderResult(ObjNoKey(1, "foo"), "entry", None, None, False)
#
#     result = sdp.add_unique(evt_digest, "entry", ObjNoKey(1, "foo"))
#     assert result == SheerkaDataProviderResult(ObjNoKey(1, "foo"), "entry", None, None, True)
#
#     result = sdp.add_unique(evt_digest, "entry", ObjNoKey(2, "bar"))
#     assert result == SheerkaDataProviderResult(ObjNoKey(2, "bar"), "entry", None, None, False)
#
#     result = sdp.add_unique(evt_digest, "entry", ObjNoKey(2, "bar"))
#     assert result == SheerkaDataProviderResult(ObjNoKey(2, "bar"), "entry", None, None, True)
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {"entry": {ObjNoKey(1, "foo"), ObjNoKey(2, "bar")}}
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_keep_state_history(root):
#     sdp = SheerkaDataProvider(root)
#
#     event1 = Event("cmd add 'foo => bar'")
#     event_digest1 = sdp.save_event(event1)
#     obj1 = "foo => bar"
#     sdp.add(event_digest1, "entry1", obj1)
#     state_digest1 = sdp.get_snapshot(SheerkaDataProvider.HeadFile)
#
#     event2 = Event("cmd add 'foo => baz'")
#     event_digest2 = sdp.save_event(event2)
#     obj2 = "foo => baz"
#     sdp.add(event_digest2, "entry2", obj2)
#     state_digest2 = sdp.get_snapshot(SheerkaDataProvider.HeadFile)
#
#     state2 = sdp.load_state(state_digest2)
#
#     assert sdp.io.exists(path.join(sdp.io.root, SheerkaDataProvider.EventFolder, event_digest1[0:24], event_digest1))
#     assert sdp.io.exists(path.join(sdp.io.root, SheerkaDataProvider.StateFolder, state_digest1[0:24], state_digest1))
#     assert sdp.io.exists(path.join(sdp.io.root, SheerkaDataProvider.EventFolder, event_digest2[0:24], event_digest2))
#     assert sdp.io.exists(path.join(sdp.io.root, SheerkaDataProvider.StateFolder, state_digest2[0:24], state_digest2))
#     assert state2.date is not None
#     assert state2.parents == [state_digest1]
#     assert state2.events == [event_digest2]
#     assert state2.data == {"entry1": "foo => bar", "entry2": "foo => baz"}
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_list_elements_when_there_is_nothing_to_list(root):
#     sdp = SheerkaDataProvider(root)
#
#     result = sdp.list("entry")
#
#     assert list(result) == []
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_list_when_no_key(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.serializer.register(PickleSerializer(lambda obj: isinstance(obj, str)))
#
#     sdp.add(evt_digest, "entry1", "foo")
#     sdp.add(evt_digest, "entry1", "bar")
#     sdp.add(evt_digest, "entry1", "baz", use_ref=True)
#     sdp.add(evt_digest, "entry2", "xyz")
#
#     result = sdp.list("entry1")
#
#     assert list(result) == ["foo", "bar", "baz"]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_list_when_key(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.serializer.register(PickleSerializer(lambda obj: isinstance(obj, ObjWithKey)))
#
#     sdp.add(evt_digest, "entry1", {"1": "foo"})
#     sdp.add(evt_digest, "entry1", {"2": "bar"})
#     sdp.add(evt_digest, "entry1", ObjWithKey("3", "value"), use_ref=True)
#     sdp.add(evt_digest, "entry2", {"4": "xxx"})
#
#     result = sdp.list("entry1")
#
#     assert list(result) == ["foo", "bar", ObjWithKey("3", "value")]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_list_when_one_element(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry1", "foo")
#     sdp.add(evt_digest, "entry2", "baz")
#
#     result = sdp.list("entry1")
#
#     assert list(result) == ["foo"]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_list_when_multiple_entries_under_the_same_key(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry", ObjWithKey("a", "b"))
#     sdp.add(evt_digest, "entry", ObjWithKey("a", "c"))
#
#     result = sdp.list("entry")
#     assert list(result) == [[ObjWithKey("a", "b"), ObjWithKey("a", "c")]]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_list_when_multiple_entries_under_the_same_key_when_reference(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.serializer.register(PickleSerializer(lambda obj: isinstance(obj, ObjWithKey)))
#
#     sdp.add(evt_digest, "entry", ObjWithKey("a", "b"), use_ref=True)
#     sdp.add(evt_digest, "entry", ObjWithKey("a", "c"), use_ref=True)
#
#     result = sdp.list("entry")
#     assert list(result) == [[ObjWithKey("a", "b"), ObjWithKey("a", "c")]]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_list_when_multiple_entries_under_the_same_entry(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry", ObjNoKey("a", "b"))
#     sdp.add(evt_digest, "entry", ObjNoKey("a", "c"))
#
#     result = sdp.list("entry")
#     assert list(result) == [ObjNoKey("a", "b"), ObjNoKey("a", "c")]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_list_when_multiple_entries_under_the_same_entry_when_reference(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.serializer.register(PickleSerializer(lambda obj: isinstance(obj, ObjNoKey)))
#
#     sdp.add(evt_digest, "entry", ObjNoKey("a", "b"), use_ref=True)
#     sdp.add(evt_digest, "entry", ObjNoKey("a", "c"), use_ref=True)
#
#     result = sdp.list("entry")
#     assert list(result) == [ObjNoKey("a", "b"), ObjNoKey("a", "c")]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_filter_on_key_for_dict(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry1", {"1": "foo"})
#     sdp.add(evt_digest, "entry1", {"2": "bar"})
#
#     result = sdp.list("entry1", lambda k, o: k == "1")
#
#     assert list(result) == ["foo"]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_filter_on_key_for_objects(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry1", ObjWithKey("a1", "b1"))
#     sdp.add(evt_digest, "entry1", ObjWithKey("a2", "b2"))
#
#     result = sdp.list("entry1", lambda k, o: k == "a1")
#
#     assert list(result) == [ObjWithKey("a1", "b1")]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_filter_on_attribute_for_dict(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry1", {"1": {"a": "a1", "b": "b1"}})
#     sdp.add(evt_digest, "entry1", {"2": {"a": "a2", "b": "b2"}})
#
#     result = sdp.list("entry1", lambda k, o: o["a"] == "a2")
#
#     assert list(result) == [{"a": "a2", "b": "b2"}]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_filter_on_attribute_for_object(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry1", ObjWithKey("a1", "b1"))
#     sdp.add(evt_digest, "entry1", ObjWithKey("a2", "b2"))
#
#     result = sdp.list("entry1", lambda k, o: o.b == "b2")
#
#     assert list(result) == [ObjWithKey("a2", "b2")]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_filter_a_list(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry1", "foo")
#     sdp.add(evt_digest, "entry1", "bar")
#
#     result = sdp.list("entry1", lambda o: o == "bar")
#
#     assert list(result) == ["bar"]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_filter_a_list_of_object(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry1", ObjNoKey("a1", "b1"))
#     sdp.add(evt_digest, "entry1", ObjNoKey("a2", "b2"))
#
#     result = sdp.list("entry1", lambda o: o.b == "b1")
#
#     assert list(result) == [ObjNoKey("a1", "b1")]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_remove_all_elements(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry1", "foo")
#     sdp.add(evt_digest, "entry1", "bar")
#
#     state_digest = sdp.remove(evt_digest, "entry1")
#     result = sdp.list("entry1")
#
#     assert sdp.io.read_text(path.join(sdp.io.root, SheerkaDataProvider.HeadFile)) == state_digest
#     assert list(result) == []
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_remove_a_element(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry1", "foo")
#     sdp.add(evt_digest, "entry1", "bar")
#
#     sdp.remove(evt_digest, "entry1", lambda o: o == "foo")
#     result = sdp.list("entry1")
#
#     assert list(result) == ["bar"]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_remove_dict_by_key(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry1", {"1": ObjNoKey("a1", "b1")})
#     sdp.add(evt_digest, "entry1", {"2": ObjNoKey("a2", "b2")})
#
#     sdp.remove(evt_digest, "entry1", lambda k, o: k == "2")
#     result = sdp.list("entry1")
#
#     assert list(result) == [ObjNoKey("a1", "b1")]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_remove_when_only_one_element(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry1", "foo")
#
#     sdp.remove(evt_digest, "entry1", lambda o: o == "foo")
#     result = sdp.list("entry1")
#
#     assert list(result) == []
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_cannot_remove_if_entry_does_not_exist(root):
#     sdp = SheerkaDataProvider(root)
#     with pytest.raises(IndexError) as e:
#         sdp.remove(evt_digest, "entry", silent_remove=False)
#     assert str(e.value) == "entry"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_no_exception_is_raise_when_remove_in_silent_mode(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.remove(evt_digest, "entry", silent_remove=True)  # default
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_cannot_modify_an_entry_without_a_key(root):
#     sdp = SheerkaDataProvider(root)
#
#     with pytest.raises(SheerkaDataProviderError) as error:
#         sdp.modify(evt_digest, "entry", None, "baz")
#
#     assert error.value.args[0] == "Key is mandatory."
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_modify_dict_with_a_key(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry", {"key1": "foo"})
#     sdp.add(evt_digest, "entry", {"key2": "bar"})
#
#     result = sdp.modify(evt_digest, "entry", "key1", "baz")
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {"entry": {"key1": "baz", "key2": "bar"}}
#     assert result.obj == "baz"
#     assert result.entry == "entry"
#     assert result.key == "key1"
#     assert result.digest is None
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_modify_an_object_with_a_key(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry", ObjWithKey("key1", "foo"))
#     sdp.add(evt_digest, "entry", ObjWithKey("key2", "bar"))
#
#     result = sdp.modify(evt_digest, "entry", "key1", ObjWithKey("key1", "baz"))
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#
#     assert state.data == {"entry": {"key1": ObjWithKey("key1", "baz"), "key2": ObjWithKey("key2", "bar")}}
#     assert result.obj == ObjWithKey("key1", "baz")
#     assert result.entry == "entry"
#     assert result.key == "key1"
#     assert result.digest is None
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_modify_an_object_while_changing_the_key(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry", ObjWithKey("key1", "foo"))
#     sdp.add(evt_digest, "entry", ObjWithKey("key2", "bar"))
#
#     result = sdp.modify(evt_digest, "entry", "key1", ObjWithKey("key3", "baz"))
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {"entry": {"key2": ObjWithKey("key2", "bar"), "key3": ObjWithKey("key3", "baz")}}
#     assert result.obj == ObjWithKey("key3", "baz")
#     assert result.entry == "entry"
#     assert result.key == "key3"
#     assert result.digest is None
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_modify_an_object_while_changing_the_key_to_an_existing_key(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry", ObjWithKey("key1", "foo"))
#     sdp.add(evt_digest, "entry", ObjWithKey("key2", "bar"))
#
#     result = sdp.modify(evt_digest, "entry", "key2", ObjWithKey("key1", "bar"))
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {"entry": {"key1": [ObjWithKey("key1", "foo"), ObjWithKey("key1", "bar")]}}
#     assert result.obj == ObjWithKey("key1", "bar")
#     assert result.entry == "entry"
#     assert result.key == "key1"
#     assert result.digest is None
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_modify_an_object_while_changing_the_key_to_an_existing_when_list(root):
#     """
#     In this example, the item to modify is within a list, and its key has changed
#     and in the new key, there is already a list
#     :return:
#     """
#     sdp = SheerkaDataProvider(root)
#
#     sdp.add(evt_digest, "entry", ObjDumpJson("key1", "value11"))
#     sdp.add(evt_digest, "entry", ObjDumpJson("key1", "value12"))
#     sdp.add(evt_digest, "entry", ObjDumpJson("key2", "value21"))
#     sdp.add(evt_digest, "entry", ObjDumpJson("key2", "value22"))
#
#     new_value = ObjDumpJson("key1", "value13")
#     setattr(new_value, Serializer.ORIGIN, ObjDumpJson("key2", "value21").get_digest())
#     result = sdp.modify(evt_digest, "entry", "key2", new_value)
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {"entry": {
#         "key1": [ObjDumpJson("key1", "value11"), ObjDumpJson("key1", "value12"), ObjDumpJson("key1", "value13")],
#         "key2": [ObjDumpJson("key2", "value22")]
#     }}
#     assert result.obj == new_value
#     assert result.entry == "entry"
#     assert result.key == "key1"
#     assert result.digest is None
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_modify_an_object_while_changing_the_key_to_an_existing_when_nothing(root):
#     """
#     In this example, the item to modify is within a list, and its key has changed
#     and in the new key, there is nothing (the new key does not exist)
#     :return:
#     """
#     sdp = SheerkaDataProvider(root)
#     sdp.serializer.register(PickleSerializer(lambda o: isinstance(o, ObjDumpJson)))
#
#     sdp.add(evt_digest, "entry", ObjDumpJson("key2", "value21"))
#     sdp.add(evt_digest, "entry", ObjDumpJson("key2", "value22"))
#
#     new_value = ObjDumpJson("key1", "value13")
#     setattr(new_value, Serializer.ORIGIN, ObjDumpJson("key2", "value21").get_digest())
#     result = sdp.modify(evt_digest, "entry", "key2", new_value)
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {"entry": {
#         "key1": ObjDumpJson("key1", "value13"),
#         "key2": [ObjDumpJson("key2", "value22")]
#     }}
#     assert result.obj == new_value
#     assert result.entry == "entry"
#     assert result.key == "key1"
#     assert result.digest is None
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_modify_an_object_while_changing_the_key_to_an_existing_when_one_item(root):
#     """
#     In this example, the item to modify is within a list, and its key has changed
#     and in the new key, there is only one element
#     :return:
#     """
#     sdp = SheerkaDataProvider(root)
#     sdp.serializer.register(PickleSerializer(lambda o: isinstance(o, ObjDumpJson)))
#
#     sdp.add(evt_digest, "entry", ObjDumpJson("key1", "value11"))
#     sdp.add(evt_digest, "entry", ObjDumpJson("key2", "value21"))
#     sdp.add(evt_digest, "entry", ObjDumpJson("key2", "value22"))
#
#     new_value = ObjDumpJson("key1", "value13")
#     setattr(new_value, Serializer.ORIGIN, ObjDumpJson("key2", "value21").get_digest())
#     result = sdp.modify(evt_digest, "entry", "key2", new_value)
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {"entry": {
#         "key1": [ObjDumpJson("key1", "value11"), ObjDumpJson("key1", "value13")],
#         "key2": [ObjDumpJson("key2", "value22")]
#     }}
#     assert result.obj == new_value
#     assert result.entry == "entry"
#     assert result.key == "key1"
#     assert result.digest is None
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_modify_a_object_saved_by_ref(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.serializer.register(PickleSerializer(lambda o: isinstance(o, ObjWithKey)))
#     sdp.add(evt_digest, "entry", ObjWithKey("key1", "foo"))
#     sdp.add(evt_digest, "entry", ObjWithKey("key2", "bar"), use_ref=True)
#
#     result = sdp.modify(evt_digest, "entry", "key2", ObjWithKey("key2", "baz"))
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {"entry": {
#         "key1": ObjWithKey("key1", "foo"),
#         "key2": "##REF##:041d3cca905b51bc2c66251e73e56b836aae7b9435ee3d7eb05d44bb67ff575e"}}
#     assert result.obj == ObjWithKey("key2", "baz")
#     assert result.entry == "entry"
#     assert result.key == "key2"
#     assert result.digest == "041d3cca905b51bc2c66251e73e56b836aae7b9435ee3d7eb05d44bb67ff575e"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_modify_an_object_saved_by_ref_in_a_list(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.serializer.register(PickleSerializer(lambda o: isinstance(o, ObjDumpJsonNoDigest)))
#
#     sdp.add(evt_digest, "entry", ObjDumpJsonNoDigest("key1", "value11"), use_ref=True)
#     sdp.add(evt_digest, "entry", ObjDumpJsonNoDigest("key1", "value12"), use_ref=True)
#     result = sdp.add(evt_digest, "entry", ObjDumpJsonNoDigest("key2", "value21"), use_ref=True)
#     sdp.add(evt_digest, "entry", ObjDumpJsonNoDigest("key2", "value22"), use_ref=True)
#
#     new_value = ObjDumpJsonNoDigest("key1", "value13")
#     setattr(new_value, Serializer.ORIGIN, result.digest)
#     result = sdp.modify(evt_digest, "entry", "key2", new_value)
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {"entry": {
#         'key1': ['##REF##:f80a0c0aceb1a7a3d238c0cff2d86d6bd3a62e0c1a65c5b505f43b10c4604bd8',
#                  '##REF##:239a8238d188c37afa10b1bcc312ca8a0e78f6e75d688ca65d08e16717ff68b0',
#                  '##REF##:9d0a2bf9d4081de0b14837ea46bc7a1cfb6b7562f7ae86255ea9bd0ac53a6437'],
#         'key2': ['##REF##:df8a38b07f469f2ff8001ea6a70f77f4f9ce85d69c530091fcaf4b380f1500d3']
#     }}
#     assert result.obj == new_value
#     assert result.entry == "entry"
#     assert result.key == "key1"
#     assert result.digest is not None
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_modify_a_data_provider_ref(root):
#     # first, create a valid entry
#     sdp = SheerkaDataProvider(root)
#     sdp.serializer.register(PickleSerializer(lambda o: isinstance(o, ObjWithDigestWithKey)))
#     obj = ObjWithDigestWithKey("1", "foo")
#     sdp.add(evt_digest, "entry", obj, use_ref=True)
#     sdp.add(evt_digest, "entry_ref", SheerkaDataProviderRef(obj.b, obj.get_digest()))
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {
#         "entry": {"1": "##REF##:1foo"},
#         "entry_ref": {"foo": SheerkaDataProviderRef(obj.b, obj.get_digest())}}
#
#     # modify this entry
#     obj_new = ObjWithDigestWithKey("1", "bar")
#     sdp.modify(evt_digest, "entry", obj_new.a, obj_new)
#     result = sdp.modify(evt_digest, "entry_ref", "foo", SheerkaDataProviderRef(obj.b, obj_new.get_digest()))
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {
#         "entry": {"1": "##REF##:1bar"},
#         "entry_ref": {"foo": SheerkaDataProviderRef(obj.b, obj_new.get_digest())}}
#
#     assert result.obj == SheerkaDataProviderRef(obj.b, obj_new.get_digest())
#     assert result.entry == "entry_ref"
#     assert result.key == "foo"
#     assert result.digest is None  # digest is not set as what is saved (the digest) is not saved by ref
#
#     # sanity check, I can load the modified entry
#     loaded = sdp.get("entry_ref", "foo")
#     assert loaded == ObjWithDigestWithKey("1", "bar")
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_modify_is_ref_when_in_list(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.serializer.register(PickleSerializer(lambda o: isinstance(o, ObjWithDigestWithKey)))
#     ref_result1 = sdp.add(evt_digest, "entry", ObjWithDigestWithKey(1, "foo"), use_ref=True)
#     ref_result2 = sdp.add(evt_digest, "entry", ObjWithDigestWithKey(2, "bar"), use_ref=True)
#
#     sdp.add(evt_digest, "entry_ref", SheerkaDataProviderRef("1", ref_result1.digest))
#     sdp.add(evt_digest, "entry_ref", SheerkaDataProviderRef("1", ref_result2.digest))
#
#     ref_result3 = sdp.add(evt_digest, "entry", ObjWithDigestWithKey(3, "baz"), use_ref=True)
#
#     result = sdp.modify(
#         evt_digest,
#         "entry_ref",
#         "1",
#         SheerkaDataProviderRef("1", ref_result3.digest, ref_result2.digest))
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {'entry': {'1': '##REF##:1foo', '2': '##REF##:2bar', '3': '##REF##:3baz'},
#                           'entry_ref': {'1': [
#                               SheerkaDataProviderRef("1", ref_result1.digest),
#                               SheerkaDataProviderRef("1", ref_result3.digest, ref_result2.digest)]}}
#
#     loaded = sdp.get("entry_ref", "1")
#     assert len(loaded) == 2
#     assert loaded[0] == ObjWithDigestWithKey(1, "foo")
#     assert loaded[1] == ObjWithDigestWithKey(3, "baz")
#
#     assert result.obj == SheerkaDataProviderRef("1", ref_result3.digest, ref_result2.digest)
#     assert result.entry == "entry_ref"
#     assert result.key == "1"
#     assert result.digest is None  # digest is not set as what is saved (the digest) is not saved by ref
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_cannot_modify_an_entry_that_does_not_exist(root):
#     sdp = SheerkaDataProvider(root)
#
#     with pytest.raises(IndexError) as e:
#         sdp.modify(evt_digest, "entry", "key", "foo")
#
#     assert str(e.value) == "entry"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_cannot_modify_a_key_that_does_not_exist(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry1", {"1": "foo"})
#
#     with pytest.raises(IndexError) as e:
#         sdp.modify(evt_digest, "entry1", "2", "bar")
#     assert str(e.value) == "entry1.2"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_cannot_modify_a_list_when_origin_is_unknown(root):
#     sdp = SheerkaDataProvider(root)
#
#     sdp.add(evt_digest, "entry", ObjWithKey("key", "value1"))
#     sdp.add(evt_digest, "entry", ObjWithKey("key", "value2"))  # same they
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#
#     with pytest.raises(SheerkaDataProviderError) as error:
#         sdp.modify(evt_digest, "entry", "key", ObjWithKey("key", "value2"))
#
#     assert error.value.obj == ObjWithKey("key", "value2")
#     assert error.value.args[0] == "Multiple entries under 'entry.key'"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_modify_a_list_when_the_origin_is_known(root):
#     sdp = SheerkaDataProvider(root)
#
#     sdp.add(evt_digest, "entry", ObjDumpJson("key", "value1"))
#     sdp.add(evt_digest, "entry", ObjDumpJson("key", "value2"))  # same they
#
#     new_value = ObjDumpJson("key", "value3")
#     setattr(new_value, Serializer.ORIGIN, ObjDumpJson("key", "value1").get_digest())
#
#     sdp.modify(evt_digest, "entry", "key", new_value)
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {"entry": {"key": [ObjDumpJson("key", "value3"), ObjDumpJson("key", "value2")]}}
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_modify_a_list_when_the_origin_is_known_2(root):
#     """
#     This time, we check that the origin is automatically set when the object was saved as a reference
#     We also check that all objects are still persisted as reference
#     :return:
#     """
#     sdp = SheerkaDataProvider(root)
#     sdp.serializer.register(PickleSerializer(lambda o: isinstance(o, ObjDumpJson)))
#
#     sdp.add(evt_digest, "entry", ObjDumpJson("key", "value1"), use_ref=True)
#     sdp.add(evt_digest, "entry", ObjDumpJson("key", "value2"), use_ref=True)  # same they
#
#     objs = sdp.get("entry", "key")  # origin is automatically set to the loaded objects
#     objs[0].value = "value3"
#
#     sdp.modify(evt_digest, "entry", "key", objs[0])
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {"entry": {"key": [
#         "##REF##:621771a3af6a331e9abb3a63fb25e0cac4b13df0b292dfa30db6bd89031bfad0",
#         "##REF##:5fe085e8366d35c5f04a18b2d3dada376128b246e07c66de5872830b00f5f517"]}}
#
#     # checks that all objects are (still) persisted
#     sdp.io.exists(
#         sdp.io.get_obj_path(sdp.ObjectsFolder, "621771a3af6a331e9abb3a63fb25e0cac4b13df0b292dfa30db6bd89031bfad0"))
#     sdp.io.exists(
#         sdp.io.get_obj_path(sdp.ObjectsFolder, "5fe085e8366d35c5f04a18b2d3dada376128b246e07c66de5872830b00f5f517"))
#     sdp.io.exists(
#         sdp.io.get_obj_path(sdp.ObjectsFolder, "1aac9e0d5c74c3bb989fd0f9def792bba36c5595d32f61be7cbb1a38dcf75327"))
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_get_the_entire_entry(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry1", "foo")
#     sdp.add(evt_digest, "entry1", "bar")
#
#     result = sdp.get("entry1")
#     result_safe = sdp.get_safe("entry1")
#
#     assert result == ["foo", "bar"]
#     assert result_safe == ["foo", "bar"]
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_get_an_entry_with_on_object(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry1", "foo")
#
#     result = sdp.get("entry1")
#     result_safe = sdp.get_safe("entry1")
#
#     assert result == "foo"
#     assert result_safe == "foo"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_get_an_entry_by_key(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry1", {"1": "foo"})
#     sdp.add(evt_digest, "entry1", {"2": "bar"})
#
#     result = sdp.get("entry1", "2")
#     result_safe = sdp.get_safe("entry1", "2")
#
#     assert result == "bar"
#     assert result_safe == "bar"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_get_object_saved_by_reference(root):
#     sdp = SheerkaDataProvider(root)
#     obj = ObjDumpJson("my_key", "value1")
#     sdp.serializer.register(JsonSerializer(core.utils.get_full_qualified_name(obj)))
#
#     result = sdp.add(evt_digest, "entry", obj, use_ref=True)
#     loaded = sdp.get(result.entry, result.key)
#
#     assert loaded == obj
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_get_objects_from_list_when_saved_by_reference(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.serializer.register(PickleSerializer(lambda o: isinstance(o, ObjDumpJson)))
#
#     sdp.add(evt_digest, "entry", ObjDumpJson("key", "value1"), use_ref=True)
#     sdp.add(evt_digest, "entry", ObjDumpJson("key", "value2"), use_ref=True)  # same they
#
#     objs = sdp.get("entry", "key")
#
#     assert objs[0] == ObjDumpJson("key", "value1")
#     assert objs[1] == ObjDumpJson("key", "value2")
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_cannot_get_an_entry_that_does_not_exist(root):
#     sdp = SheerkaDataProvider(root)
#
#     assert sdp.get_safe("entry") is None
#     with pytest.raises(IndexError) as e:
#         sdp.get("entry")
#     assert str(e.value) == "entry"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_cannot_get_a_key_that_does_not_exist(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.add(evt_digest, "entry1", {"1": "foo"})
#
#     assert sdp.get_safe("entry1", "2") is None
#     with pytest.raises(IndexError) as e:
#         sdp.get("entry1", "2")
#     assert str(e.value) == "entry1.2"
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_save_and_retrieve_cache(root):
#     sdp = SheerkaDataProvider(root)
#     txt = "foo bar baz foo bar baz foo bar baz"
#     key = "key_to_use"
#     category = "cache_category"
#
#     assert not sdp.in_cache(category, key)
#     digest = sdp.add_to_cache(category, key, txt)
#     assert sdp.io.exists(path.join(sdp.io.root, SheerkaDataProvider.CacheFolder, digest[0:24], digest))
#     assert sdp.in_cache(category, key)
#
#     from_cache = sdp.load_from_cache(category, key)
#     assert from_cache == txt
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_cache_is_not_updated_by_default(root):
#     sdp = SheerkaDataProvider(root)
#     txt = "foo bar baz foo bar baz foo bar baz"
#     txt2 = "foo foo foo foo foo foo foo foo foo"
#     key = "key_to_use"
#     category = "cache_category"
#
#     sdp.add_to_cache(category, key, txt)
#     sdp.add_to_cache(category, key, txt2)
#
#     from_cache = sdp.load_from_cache(category, key)
#     assert from_cache == txt
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_update_cache(root):
#     sdp = SheerkaDataProvider(root)
#     txt = "foo bar baz foo bar baz foo bar baz"
#     txt2 = "foo foo foo foo foo foo foo foo foo"
#     key = "key_to_use"
#     category = "cache_category"
#
#     sdp.add_to_cache(category, key, txt)
#     sdp.add_to_cache(category, key, txt2, update=True)
#
#     from_cache = sdp.load_from_cache(category, key)
#     assert from_cache == txt2
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_remove_from_cache(root):
#     sdp = SheerkaDataProvider(root)
#     txt = "foo bar baz foo bar baz foo bar baz"
#     key = "key_to_use"
#     category = "cache_category"
#
#     sdp.add_to_cache(category, key, txt)
#     digest = sdp.remove_from_cache(category, key)
#     assert not sdp.io.exists(path.join(sdp.io.root, SheerkaDataProvider.CacheFolder, digest[0:24], digest))
#     assert not sdp.in_cache(category, key)
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_test_than_an_entry_exists(root):
#     sdp = SheerkaDataProvider(root)
#
#     assert not sdp.exists("entry")
#     sdp.add(evt_digest, "entry", "value")
#     assert sdp.exists("entry")
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_test_if_a_key_exists(root):
#     sdp = SheerkaDataProvider(root)
#     obj = ObjWithDigestWithKey("key", "value")
#
#     assert not sdp.exists("entry")
#     assert not sdp.exists("entry", obj.get_key())
#
#     sdp.add(evt_digest, "entry", obj)
#     assert not sdp.exists("entry", "wrong_key")
#     assert sdp.exists("entry", obj.get_key())
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_test_that_the_object_exists(root):
#     sdp = SheerkaDataProvider(root)
#     obj = ObjWithDigestWithKey("key", "value")
#
#     assert not sdp.exists("entry")
#     assert not sdp.exists("entry", obj.get_key())
#     assert not sdp.exists("entry", obj.get_key(), obj.get_digest())
#
#     # test for a single item under the key
#     sdp.add(evt_digest, "entry", obj)
#     assert not sdp.exists("entry", obj.get_key(), "wrong_digest")
#     assert sdp.exists("entry", obj.get_key(), obj.get_digest())
#
#     # test for a list item under the key
#     sdp.add(evt_digest, "entry2", ObjWithDigestWithKey("key", "value2"))
#     assert not sdp.exists("entry2", obj.get_key(), obj.get_digest())
#
#     sdp.add(evt_digest, "entry2", ObjWithDigestWithKey("key", "value3"))
#     assert not sdp.exists("entry2", obj.get_key(), obj.get_digest())
#
#     sdp.add(evt_digest, "entry2", obj)
#     assert sdp.exists("entry2", obj.get_key(), obj.get_digest())
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_test_than_the_object_exists_when_using_references(root):
#     sdp = SheerkaDataProvider(root)
#     sdp.serializer.register(PickleSerializer(lambda o: isinstance(o, ObjWithDigestWithKey)))
#     obj = ObjWithDigestWithKey("key", "value")
#
#     assert not sdp.exists("entry")
#     assert not sdp.exists("entry", obj.get_key())
#     assert not sdp.exists("entry", obj.get_key(), obj.get_digest())
#
#     # test for a single item under the key
#     sdp.add(evt_digest, "entry", obj, use_ref=True)
#     assert not sdp.exists("entry", obj.get_key(), "wrong_digest")
#     assert sdp.exists("entry", obj.get_key(), obj.get_digest())
#
#     # test for a list item under the key
#     sdp.add(evt_digest, "entry2", ObjWithDigestWithKey("key", "value2"), use_ref=True)
#     assert not sdp.exists("entry2", obj.get_key(), obj.get_digest())
#
#     sdp.add(evt_digest, "entry2", ObjWithDigestWithKey("key", "value3"), use_ref=True)
#     assert not sdp.exists("entry2", obj.get_key(), obj.get_digest())
#
#     sdp.add(evt_digest, "entry2", obj, use_ref=True)
#     assert sdp.exists("entry2", obj.get_key(), obj.get_digest())
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_save_and_load_object_ref_with_history(root):
#     sdp = SheerkaDataProvider(root)
#     obj = ObjDumpJson("my_key", "value1")
#     sdp.serializer.register(JsonSerializer(core.utils.get_full_qualified_name(obj)))
#
#     result = sdp.add(evt_digest, "entry", obj, use_ref=True)
#     loaded = sdp.get(result.entry, result.key)
#     history = getattr(loaded, Serializer.HISTORY)
#
#     assert result.obj == obj
#     assert result.entry == "entry"
#     assert result.key == obj.key
#     assert result.digest == obj.get_digest()
#
#     assert loaded.key == obj.key
#     assert loaded.value == obj.value
#
#     assert history[Serializer.USERNAME] == "kodjo"
#     assert history[Serializer.MODIFICATION_DATE] != ""
#     assert history[Serializer.PARENTS] == []
#
#     assert sdp.io.exists(sdp.io.get_obj_path(sdp.ObjectsFolder, obj.get_digest()))
#
#     # save a second type with no modification
#     previous_modification_time = history[Serializer.MODIFICATION_DATE]
#     previous_parents = history[Serializer.PARENTS]
#
#     sdp.modify(evt_digest, "entry", result.key, loaded)
#     loaded = sdp.get(result.entry, result.key)
#     history = getattr(loaded, Serializer.HISTORY)
#
#     assert history[Serializer.MODIFICATION_DATE] == previous_modification_time
#     assert history[Serializer.PARENTS] == previous_parents
#
#     # save again, but with a modification
#     previous_digest = loaded.get_digest()
#     loaded.value = "value2"
#
#     sdp.modify(evt_digest, "entry", result.key, loaded)
#     loaded2 = sdp.get(result.entry, result.key)
#     history2 = getattr(loaded2, Serializer.HISTORY)
#
#     assert loaded2.key == loaded.key
#     assert loaded2.value == loaded.value
#
#     assert history2[Serializer.USERNAME] == "kodjo"
#     assert history2[Serializer.MODIFICATION_DATE] != ""
#     assert history2[Serializer.PARENTS] == [previous_digest]
#
#     state = sdp.load_state(sdp.get_snapshot(SheerkaDataProvider.HeadFile))
#     assert state.data == {"entry": {
#         "my_key": '##REF##:e6bf5b56428cfce0f08c94f2c3625dc3b3a8180d7229eaa9f8aa967fb16e5256'}}
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_can_add_obj_with_same_key_and_get_them_back(root):
#     sdp = SheerkaDataProvider(root)
#     obj1 = ObjDumpJson("key", "value1")
#     obj2 = ObjDumpJson("key", "value2")
#     sdp.serializer.register(JsonSerializer(core.utils.get_full_qualified_name(obj1)))
#
#     result = sdp.add(evt_digest, "entry", obj1, use_ref=True)
#     sdp.add(evt_digest, "entry", obj2, use_ref=True)
#
#     loaded = sdp.get(result.entry, result.key)
#
#     assert len(loaded) == 2
#     assert loaded[0] == obj1
#     assert loaded[1] == obj2
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_get_safe_dictionary_without_origin(root):
#     sdp = SheerkaDataProvider(root)
#     obj = {"my_key": "value1"}
#
#     obj_serializer = JsonSerializer(core.utils.get_full_qualified_name(obj))
#     sdp.serializer.register(obj_serializer)
#
#     result = sdp.add(evt_digest, "entry", obj, use_ref=True)
#     from_db = sdp.get(result.entry, result.key)
#
#     assert len(from_db) == 2
#     assert from_db["my_key"] == obj["my_key"]
#     assert Serializer.ORIGIN in from_db
#
#     from_db_no_origin = sdp.get_safe(result.entry, result.key, load_origin=False)
#     assert len(from_db_no_origin) == 1
#     assert from_db_no_origin["my_key"] == obj["my_key"]
#     assert Serializer.ORIGIN not in from_db_no_origin
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_get_dictionary_without_origin(root):
#     sdp = SheerkaDataProvider(root)
#     obj = {"my_key": "value1"}
#
#     obj_serializer = JsonSerializer(core.utils.get_full_qualified_name(obj))
#     sdp.serializer.register(obj_serializer)
#
#     result = sdp.add(evt_digest, "entry", obj, use_ref=True)
#     from_db = sdp.get(result.entry, result.key)
#
#     assert len(from_db) == 2
#     assert from_db["my_key"] == obj["my_key"]
#     assert Serializer.ORIGIN in from_db
#
#     from_db_no_origin = sdp.get(result.entry, result.key, load_origin=False)
#     assert len(from_db_no_origin) == 1
#     assert from_db_no_origin["my_key"] == obj["my_key"]
#     assert Serializer.ORIGIN not in from_db_no_origin
#
#
# @pytest.mark.parametrize("root", [
#     ".sheerka",
#     "mem://"
# ])
# def test_i_get_safe_object_without_origin(root):
#     sdp = SheerkaDataProvider(root)
#     obj = ObjDumpJson("my_key", "value1")
#
#     obj_serializer = JsonSerializer(core.utils.get_full_qualified_name(obj))
#     sdp.serializer.register(obj_serializer)
#
#     result = sdp.add(evt_digest, "entry", obj, use_ref=True)
#     from_db = sdp.get(result.entry, result.key)
#
#     assert from_db == obj
#     assert hasattr(from_db, Serializer.ORIGIN)
#
#     from_db_no_origin = sdp.get_safe(result.entry, result.key, load_origin=False)
#     assert from_db_no_origin == obj
#     assert not hasattr(from_db_no_origin, Serializer.ORIGIN)
#
#
# def test_i_can_get_ref():
#     sdp = SheerkaDataProvider("mem://")
#     obj = ObjDumpJson("my_key", "value1")
#
#     obj_serializer = JsonSerializer(core.utils.get_full_qualified_name(obj))
#     sdp.serializer.register(obj_serializer)
#
#     result = sdp.add(evt_digest, "entry", obj, use_ref=True)
#
#     ref = sdp.get_ref(result.entry, result.key)
#     assert ref == "076f0df0f110c304982242a88088efacce71f361e49f065db75919a7f72c2821"
#
#
# def test_i_can_get_ref_when_list():
#     sdp = SheerkaDataProvider("mem://")
#
#     obj_serializer = JsonSerializer(core.utils.get_full_qualified_name(ObjDumpJson))
#     sdp.serializer.register(obj_serializer)
#
#     sdp.add(evt_digest, "entry", ObjDumpJson("my_key", "value1"), use_ref=True)
#     result = sdp.add(evt_digest, "entry", ObjDumpJson("my_key", "value2"), use_ref=True)
#
#     ref = sdp.get_ref(result.entry, result.key)
#     assert ref == [
#         "076f0df0f110c304982242a88088efacce71f361e49f065db75919a7f72c2821",
#         "e6bf5b56428cfce0f08c94f2c3625dc3b3a8180d7229eaa9f8aa967fb16e5256"
#     ]
#
#
# def test_i_cannot_get_ref_if_the_saved_item_is_not_a_ref():
#     sdp = SheerkaDataProvider("mem://")
#     obj = ObjDumpJson("my_key", "value1")
#     result = sdp.add(evt_digest, "entry", obj, use_ref=False)
#
#     with pytest.raises(SheerkaDataProviderError) as e:
#         sdp.get_ref(result.entry, result.key)
#
#     assert e.value.args[0] == "Not a reference"
#     assert e.value.obj == f"{result.entry}.{result.key}"
#
#
# def test_i_cannot_get_ref_if_the_item_does_not_exist():
#     sdp = SheerkaDataProvider("mem://")
#     with pytest.raises(IndexError):
#         sdp.get_ref("fake", "fake")