This commented-out code seems unnecessary.

katyhuff · katyhuff · commit 442163b5e876 · 2013-06-28T17:38:08.000-05:00
diff --git a/lib/matplotlib/rcsetup.py b/lib/matplotlib/rcsetup.py
@@ -133,7 +133,6 @@ def validate_fonttype(s):
         return fonttype
 
 
-#validate_backend = ValidateInStrings('backend', all_backends, ignorecase=True)
 _validate_standard_backends = ValidateInStrings('backend',
                                                 all_backends,
                                                 ignorecase=True)
