nl_tokens: Get the buffer for a key .
pl_tokens: function key ( obj , vonly ) { var buffer = new Buffer ( 0 ) , item ; if ( obj . expiry !== undefined && ! vonly ) { buffer = this . expiry ( obj . expiry ) ; } item = this [ obj . rtype ] ( obj , vonly ) ; return Buffer . concat ( [ buffer , item ] , buffer . length + <mask> . length ) }