Change "NoneType" to "None". Add missing imports.

python3/atexit.py

@@ -3,14 +3,16 @@
 # for a more percise manual annotation of this module.
 # Feel free to edit the source below, but remove this header when you do.
 
-def _clear() -> NoneType: pass
+from typing import List, Tuple, Dict, Undefined, GenericType
+
+def _clear() -> None: pass
 
 def _ncallbacks() -> long: pass
 
-def _run_exitfuncs() -> NoneType: pass
+def _run_exitfuncs() -> None: pass
 
 def register(*args, **kwargs) -> object:
-    raise TypeError()
     raise MemoryError()
+    raise TypeError()
 
-def unregister(*args, **kwargs) -> NoneType: pass
+def unregister(*args, **kwargs) -> None: pass