code: def master_for(self, service):
          
          # TODO: make it coroutine and connect minsize connections
          if service not in self._masters:
              self._masters[service] = ManagedPool(
                  self, service, is_master=True,
                  db=self._redis_db,
                  password=self._redis_password,
                  encoding=self._redis_encoding,
                  minsize=self._redis_minsize,
                  maxsize=self._redis_maxsize,
                  ssl=self._redis_ssl,
                  parser=self._parser_class,
                  loop=self._loop)
          return self._masters[service]
docs: Returns wrapper to master's pool for requested service.