def _query(self, query, servers, timeout, filter):
        """
        Issue one query and return a L{Deferred} which fires with its response.

        @param query: The query to issue.
        @type query: L{dns.Query}

        @param servers: The servers which might have an answer for this
            query.
        @type servers: L{list} of L{tuple} of L{str} and L{int}

        @param timeout: A timeout on how long to wait for the response.
        @type timeout: L{tuple} of L{int}

        @param filter: A flag indicating whether to filter the results.  If
            C{True}, the returned L{Deferred} will fire with a three-tuple of
            lists of L{twisted.names.dns.RRHeader} (like the return value of
            the I{lookup*} methods of L{IResolver}.  IF C{False}, the result
            will be a L{Message} instance.
        @type filter: L{bool}

        @return: A L{Deferred} which fires with the response or a timeout
            error.
        @rtype: L{Deferred}
        """
        r = self._resolverFactory(servers=servers, reactor=self._reactor)
        d = r.queryUDP([query], timeout)
        if filter:
            d.addCallback(r.filterAnswers)
        return d

        Issue one query and return a L{Deferred} which fires with its response.

        @param query: The query to issue.
        @type query: L{dns.Query}

        @param servers: The servers which might have an answer for this
            query.
        @type servers: L{list} of L{tuple} of L{str} and L{int}

        @param timeout: A timeout on how long to wait for the response.
        @type timeout: L{tuple} of L{int}

        @param filter: A flag indicating whether to filter the results.  If
            C{True}, the returned L{Deferred} will fire with a three-tuple of
            lists of L{twisted.names.dns.RRHeader} (like the return value of
            the I{lookup*} methods of L{IResolver}.  IF C{False}, the result
            will be a L{Message} instance.
        @type filter: L{bool}

        @return: A L{Deferred} which fires with the response or a timeout
            error.
        @rtype: L{Deferred}
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/names/root.py