1 files changed, 12 insertions, 3 deletions
diff --git a/Lib/fontTools/ttLib/__init__.py b/Lib/fontTools/ttLib/__init__.py
index dadd7f20..ed00764f 100644
--- a/Lib/fontTools/ttLib/__init__.py
+++ b/Lib/fontTools/ttLib/__init__.py
@@ -6,12 +6,21 @@ import logging
 
 log = logging.getLogger(__name__)
 
-class TTLibError(Exception): pass
+
+class TTLibError(Exception):
+    pass
+
+
+class TTLibFileIsCollectionError(TTLibError):
+    pass
+
 
 @deprecateFunction("use logging instead", category=DeprecationWarning)
 def debugmsg(msg):
-	import time
-	print(msg + time.strftime("  (%H:%M:%S)", time.localtime(time.time())))
+    import time
+
+    print(msg + time.strftime("  (%H:%M:%S)", time.localtime(time.time())))
+
 
 from fontTools.ttLib.ttFont import *
 from fontTools.ttLib.ttCollection import TTCollection