Fixed #20: I can parse simple concepts

tests/caching/test_ListIfNeededCache.py

@@ -610,6 +610,17 @@ class TestListIfNeededCache(BaseTest):
         assert cache.to_add == set()
         assert cache.to_remove == set()
 
+    def test_deleting_an_entry_that_does_not_exist_from_a_list_is_not_an_error(self):
+        cache = ListIfNeededCache()
+        cache.put("key", "value1")
+        cache.put("key", "value2")
+        cache.reset_events()
+
+        cache.delete("key", "value3")
+        assert len(cache) == 2
+        assert cache.to_add == set()
+        assert cache.to_remove == set()
+
     def test_i_can_delete_when_alt_sdp_and_cache_is_cleared(self):
         cache = ListIfNeededCache(sdp=FakeSdp(get_value=lambda entry, k: NotFound)).auto_configure("cache_name")
         alt_sdp = FakeSdp(get_alt_value=lambda cache_name, key: "value",
@@ -645,4 +656,4 @@ class TestListIfNeededCache(BaseTest):
 
         assert cache.copy() == {"key": "value"}
         assert cache.to_remove == set()
-        assert cache.to_add == {"key"}
+        assert cache.to_add == {"key"}