Issue #18432:  Fix unintended API change in the sched module
diff --git a/Lib/sched.py b/Lib/sched.py
index ccf8ce9..b9a7ad1 100644
--- a/Lib/sched.py
+++ b/Lib/sched.py
@@ -165,4 +165,4 @@
         # the actual order they would be retrieved.
         with self._lock:
             events = self._queue[:]
-            return map(heapq.heappop, [events]*len(events))
+            return list(map(heapq.heappop, [events]*len(events)))