code: def getSignedNS(self, ns_uri):
          
          msg_args = self.message.getArgs(ns_uri)
  
          for key in msg_args.iterkeys():
              if not self.isSigned(ns_uri, key):
                  logging.info("SuccessResponse.getSignedNS: (%s, %s) not signed."
                              % (ns_uri, key))
                  return None
  
          return msg_args
docs: Get signed arguments from the response message.  Return a
          dict of all arguments in the specified namespace.  If any of
          the arguments are not signed, return None.