asyncio doc: remove reference to _DEBUG (now replaced with PYTHONASYNCIODEBUG
env var), document the default debug mode
diff --git a/Doc/library/asyncio-eventloop.rst b/Doc/library/asyncio-eventloop.rst
index 04b182b..92c4978 100644
--- a/Doc/library/asyncio-eventloop.rst
+++ b/Doc/library/asyncio-eventloop.rst
@@ -558,7 +558,7 @@
.. method:: BaseEventLoop.get_debug()
- Get the debug mode (:class:`bool`) of the event loop.
+ Get the debug mode (:class:`bool`) of the event loop, ``False`` by default.
.. method:: BaseEventLoop.set_debug(enabled: bool)