code: func (d *driver) RevokeExternalConnectivity(nid, eid string) error {
  	data := &api.RevokeExternalConnectivityRequest{
  		NetworkID:  nid,
  		EndpointID: eid,
  	}
  	err := d.call("RevokeExternalConnectivity", data, &api.RevokeExternalConnectivityResponse{})
  	if err != nil && plugins.IsNotFound(err) {
  		// It is not mandatory yet to support this method
  		return nil
  	}
  	return err
  }
docs: // RevokeExternalConnectivity method is invoked to remove any external connectivity programming related to the endpoint.