Fix type hints and small bugs

none/sched.py

@@ -0,0 +1,11 @@
+try:
+    from apscheduler.schedulers.asyncio import AsyncIOScheduler
+except ImportError:
+    # APScheduler is not installed
+    AsyncIOScheduler = None
+
+if AsyncIOScheduler:
+    class Scheduler(AsyncIOScheduler):
+        pass
+else:
+    Scheduler = None