more typing cleanup

nbclient/tests/test_client.py

@@ -217,7 +217,7 @@ def test_mock_wrapper(self):
                 execute=MagicMock(return_value=parent_id),
                 is_alive=MagicMock(return_value=make_async(True)),
             )
-            executor.parent_id = parent_id  # type:ignore
+            executor.parent_id = parent_id
             return func(self, executor, cell_mock, message_mock)
 
         return test_mock_wrapper

nbclient/util.py

@@ -6,7 +6,7 @@
 import asyncio
 import inspect
 import sys
-from typing import Any, Awaitable, Callable, Optional, Union
+from typing import Any, Awaitable, Callable, Optional, TypeVar, Union
 
 
 def check_ipython() -> None:
@@ -62,7 +62,10 @@ def just_run(coro: Awaitable) -> Any:
     return loop.run_until_complete(coro)
 
 
-def run_sync(coro: Callable) -> Callable:
+
+T = TypeVar("T")
+
+def run_sync(coro: Callable[..., T]) -> Callable[..., T]:
     """Runs a coroutine and blocks until it has executed.
 
     An event loop is created if no one already exists. If an event loop is