def locked_get(self):
    credentials = None
    try:
      f = open(self._filename, 'rb')
      content = f.read()
      f.close()
    except IOError:
      return credentials

    try:
      credentials = Credentials.new_from_json(content)
      credentials.set_store(self)
    except ValueError:
      pass

    return credentials
:comparison_attr        - the attribute of the objects we are lookig at that will be used for determiniing truth
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/google-api-python-client/oauth2client/file.py/Storage.locked_get--crossover with--dataset/ETHPy150Open Neohapsis/bbqsql/bbqsql/lib/requester.py/Requester.__init__