Update exasol_udf_mock_python/mock_context.py

Co-authored-by: Torsten Kilias <[email protected]>

exasol_udf_mock_python/mock_context.py

@@ -30,7 +30,7 @@ def __init__(self, input_groups: Iterator[Group], metadata: MockMetaData):
         """ Mock context for the current group """
         self._current:Optional[StandaloneMockContext] = None
         """ Output for all groups """
-        self._previous_groups = []        # type: List[Group]
+        self._previous_groups: List[Group] = []
 
     def _next_group(self) -> bool:
         """