nl_tokens: Sets a key - value pair in this instance .
pl_tokens: function ( key , value ) { var index = this . _keys . indexOf ( key ) ; if ( <mask> > - 1 ) { this . _keys [ index ] = key ; this . _values [ index ] = value ; } else { this . _keys . push ( key ) ; this . _values . push ( value ) ; } return this ; }