docs: def set_queue_metadata(self, queue_name, metadata=None, timeout=None):
          '''
          Sets user-defined metadata on the specified queue. Metadata is
          associated with the queue as name-value pairs.
  
          :param str queue_name:
              The name of an existing queue.
          :param dict metadata:
              A dict containing name-value pairs to associate with the
              queue as metadata.
          :param int timeout:
              The server timeout, expressed in seconds.
          '''
          _validate_not_none('queue_name', queue_name)
          request = HTTPRequest()
          request.method = 'PUT'
          request.host = self._get_host()
          request.path = _get_path(queue_name)
          request.query = [
              ('comp', 'metadata'),
              ('timeout', _int_to_str(timeout)),
          ]
          request.headers = [('x-ms-meta-name-values', metadata)]
          self._perform_request(request)