do not pop future

Author: kumaraditya303

Lib/asyncio/streams.py

@@ -144,8 +144,7 @@ def resume_writing(self):
         if self._loop.get_debug():
             logger.debug("%r resumes writing", self)
 
-        while self._drain_waiters:
-            waiter = self._drain_waiters.popleft()
+        for waiter in self._drain_waiters:
             if not waiter.done():
                 waiter.set_result(None)
 
@@ -155,8 +154,7 @@ def connection_lost(self, exc):
         if not self._paused:
             return
 
-        while self._drain_waiters:
-            waiter = self._drain_waiters.popleft()
+        for waiter in self._drain_waiters:
             if not waiter.done():
                 if exc is None:
                     waiter.set_result(None)