Docserver: there is only one.

chrome/common/extensions/docs/server2/blob_reference_store.py

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 from appengine_wrappers import db
 from appengine_wrappers import BlobReferenceProperty
 
 BLOB_REFERENCE_BLOBSTORE = 'BlobReferenceBlobstore'
 
 class _Model(db.Model):
   key_ = db.StringProperty()
   value = BlobReferenceProperty()
 
 class BlobReferenceStore(object):
   """A wrapper around the datastore API that can store blob keys.
   """
-  def __init__(self, branch):
-    self._branch = branch
-
   def _Query(self, namespace, key):
     return _Model.gql('WHERE key_ = :1', self._MakeKey(namespace, key)).get()
 
   def _MakeKey(self, namespace, key):
-    return '.'.join([self._branch, namespace, key])
+    return '.'.join((namespace, key))
 
   def Set(self, namespace, key, value):
     _Model(key_=self._MakeKey(namespace, key), value=value).put()
 
   def Get(self, namespace, key):
     result = self._Query(namespace, key)
     if not result:
       return None
     return result.value
 
   def Delete(self, namespace, key):
     result = self._Query(namespace, key)
     if not result:
       return None
     blob_key = result.value
     result.delete()
     return blob_key