fix merge mistake

slither/core/declarations/contract.py

@@ -193,6 +193,7 @@ class Contract(SourceMapping):  # pylint: disable=too-many-public-methods
     def comments(self, comments: str):
         self._comments = comments
 
+    @property
     def is_fully_implemented(self) -> bool:
         return self._is_fully_implemented
 

tests/test_features.py

@@ -210,7 +210,7 @@ def test_abstract_contract() -> None:
     assert not slither.contracts[0].is_fully_implemented
 
     solc_select.switch_global_version("0.5.0", always_install=True)
-    slither = Slither("./tests/function_features/abstract.sol")
+    slither = Slither("./tests/function_features/implicit_abstract.sol")
     assert not slither.contracts[0].is_fully_implemented
 
     slither = Slither(