Starts a server on the port provided in the :class:`Server` constructor
        in a separate thread

        :rtype: Server
        :returns: server instance for chaining

def start(self):
        '''
        Starts a server on the port provided in the :class:`Server` constructor
        in a separate thread

        :rtype: Server
        :returns: server instance for chaining
        '''
        self._handler = _create_handler_class(self._rules, self._always_rules)
        self._server = HTTPServer(('', self._port), self._handler)
        self._thread = Thread(target=self._server.serve_forever, daemon=True)
        self._thread.start()
        self.running = True
        return self