1 files changed, 12 insertions, 1 deletions
diff --git a/cache_manager.py b/cache_manager.py
index e0f7f90..ed88aa9 100644
--- a/cache_manager.py
+++ b/cache_manager.py
@@ -28,7 +28,7 @@ from bzrlib.plugins.fastimport import (
 from bzrlib.plugins.fastimport.reftracker import (
     RefTracker,
     )
-from fastimport.helpers import (
+from bzrlib.plugins.fastimport.helpers import (
     single_plural,
     )
 
@@ -275,3 +275,14 @@ class CacheManager(object):
         return content
 
 
+def invert_dictset(d):
+    """Invert a dictionary with keys matching a set of values, turned into lists."""
+    # Based on recipe from ASPN
+    result = {}
+    for k, c in d.iteritems():
+        for v in c:
+            keys = result.setdefault(v, [])
+            keys.append(k)
+    return result
+
+