bpo-34344 Fix AbstractEventLoopPolicy.get_event_loop docstring (pythonGH-16463)

Author: idomic

Lib/asyncio/events.py

@@ -630,9 +630,9 @@ def __init__(self):
         self._local = self._Local()
 
     def get_event_loop(self):
-        """Get the event loop.
+        """Get the event loop for the current context.
 
-        This may be None or an instance of EventLoop.
+        Returns an instance of EventLoop or raises an exception.
         """
         if (self._local._loop is None and
                 not self._local._set_called and