Set gateway type

        Args:
            name  (str): gateway-name
            type (str): gateway-type
            callback (function): A function executed upon completion of the
                method.

        Returns:
            Return value of `callback`.

        Raises:
            None

def hwvtep_set_overlaygw_type(self, **kwargs):
        """
        Set gateway type

        Args:
            name  (str): gateway-name
            type (str): gateway-type
            callback (function): A function executed upon completion of the
                method.

        Returns:
            Return value of `callback`.

        Raises:
            None
        """
        name = kwargs.pop('name')
        type = kwargs.pop('type')
        ip_args = dict(name=name, gw_type=type)
        method_name = 'overlay_gateway_gw_type'
        method_class = self._brocade_tunnels
        gw_attr = getattr(method_class, method_name)
        config = gw_attr(**ip_args)
        output = self._callback(config)
        return output