Fix black formatting again

Author: Cito

graphql/execution/executors/asyncio.py

@@ -32,20 +32,23 @@ def ensure_future(coro_or_future, loop=None):  # type: ignore
         else:
             raise TypeError("A Future, a coroutine or an awaitable is required")
 
+
 try:
     from inspect import isasyncgen  # type: ignore
 except Exception:
 
     def isasyncgen(object):  # type: ignore
         False
 
+
 try:
     from .asyncio_utils import asyncgen_to_observable
 except Exception:
 
     def asyncgen_to_observable(asyncgen, loop=None):
         pass
 
+
 class AsyncioExecutor(object):
     def __init__(self, loop=None):
         # type: (Optional[_UnixSelectorEventLoop]) -> None