code: def stats(self, key=None):
          
          # TODO: Stats with key is not working.
  
          returns = {}
          for server in self.servers:
              returns[server.server] = server.stats(key)
  
          return returns
docs: Return server stats.
  
          :param key: Optional if you want status from a key.
          :type key: six.string_types
          :return: A dict with server stats
          :rtype: dict