Added simple form of concept composition

tests/test_PythonWithConceptsParser.py

@@ -41,17 +41,19 @@ def to_str_ast(expression):
     return PythonNode.get_dump(ast.parse(expression, mode="eval"))
 
 
-@pytest.mark.parametrize("text", [
-    "not parser result",
-    ParserResultConcept(value="not a list"),
-    ParserResultConcept(value=[]),
-    ParserResultConcept(value=["not a Node"]),
+@pytest.mark.parametrize("text, interested", [
+    ("not parser result", False),
+    (ParserResultConcept(parser="not multiple_concepts_parser"), False),
+    (ParserResultConcept(parser=multiple_concepts_parser, value=[]), True),
 ])
-def test_not_interested(text):
+def test_not_interested(text, interested):
     context = get_context()
 
     res = PythonWithConceptsParser().parse(context, text)
-    assert res is None
+    if interested:
+        assert res is not None
+    else:
+        assert res is None
 
 
 def test_i_can_parse_concepts_and_python():