nl_tokens: get the full head system definition ( latest revision )
pl_tokens: function ( identifier , <mask> , cb ) { logger . info ( 'get head system: ' + identifier ) ; var systemId = _sr . findSystem ( identifier ) ; if ( ! systemId ) { logger . error ( ERR_NOSYSID ) ; return cb ( new Error ( ERR_NOSYSID ) ) ; } _sr . getHead ( systemId , target , cb ) ; }