code: def hwvtep_attach_vlan_vid(self, **kwargs):
          
          name = kwargs.pop('name')
          mac = kwargs.pop('mac')
          vlan = kwargs.pop('vlan')
          name_args = dict(name=name, vid=vlan, mac=mac)
          method_name = 'overlay_gateway_attach_vlan_mac'
          method_class = self._brocade_tunnels
          gw_attr = getattr(method_class, method_name)
          config = gw_attr(**name_args)
          output = self._callback(config)
          return output
docs: Identifies exported VLANs in VXLAN gateway configurations.
  
          Args:
              name (str): overlay_gateway name
              vlan(str):  vlan_id range
              callback (function): A function executed upon completion of the
                   method.
  
          Returns:
             Return value of `callback`.
  
          Raises:
              None