Correct minor typo

yuvallanger · web-flow · commit 3d66a02bf516 · 2017-10-16T12:00:43.000+03:00
diff --git a/examples/event_handling/poly_editor.py b/examples/event_handling/poly_editor.py
@@ -14,7 +14,7 @@
 
 class PolygonInteractor(object):
     """
-    An polygon editor.
+    A polygon editor.
 
     Key-bindings
 
