(self)
return (self.upcoming_scheduled_visits().
                select_raw("1").
                slash("@id"))
{visit}/[next_visits][within_window][1]/@id
{visit}/[next_visits][within_window][1]/
{ visit } / [ next_visits ] [ within_window ] [ 1 ] /
def next_visit_id(self):
        """{visit}/[next_visits][within_window][1]/@id"""
        return (self.upcoming_scheduled_visits().
                select_raw("1").
                slash("@id"))
def next_visit_id ( self ) : return ( self . upcoming_scheduled_visits ( ) . select_raw ( "1" ) . slash ( "@id" ) )