Correct “an” → “a” with “Unicode”, “user”, “UTF”, etc
This affects documentation, code comments, and a debugging messages.
diff --git a/Lib/heapq.py b/Lib/heapq.py
index 07af37e..0b3e89a 100644
--- a/Lib/heapq.py
+++ b/Lib/heapq.py
@@ -54,7 +54,7 @@
In the tree above, each cell `k' is topping `2*k+1' and `2*k+2'. In
-an usual binary tournament we see in sports, each cell is the winner
+a usual binary tournament we see in sports, each cell is the winner
over the two cells it tops, and we can trace the winner down the tree
to see all opponents s/he had. However, in many computer applications
of such tournaments, we do not need to trace the history of a winner.