Try even more serious way to hide contextvars from 3.6

asgiref/sync.py

@@ -5,7 +5,7 @@
 import threading
 import weakref
 from concurrent.futures import Future, ThreadPoolExecutor
-from typing import Any, Dict
+from typing import Any, Dict, TYPE_CHECKING
 
 from .current_thread_executor import CurrentThreadExecutor
 from .local import Local
@@ -311,9 +311,10 @@ class SyncToAsync:
 
     # Maintain a contextvar for the current execution context. Optionally used
     # for thread sensitive mode.
-    thread_sensitive_context: Any = (
-        contextvars.ContextVar("thread_sensitive_context") if contextvars else None
-    )
+    if not TYPE_CHECKING:
+        thread_sensitive_context = (
+            contextvars.ContextVar("thread_sensitive_context") if contextvars else None
+        )
 
     # Maintaining a weak reference to the context ensures that thread pools are
     # erased once the context goes out of scope. This terminates the thread pool.