nl_tokens: Pop object from array or nil if none are left . Works just like pop () but it is KVO - compliant .
pl_tokens: function ( ) { var len = <mask> ( this , 'length' ) ; if ( len === 0 ) return null ; var ret = this . objectAt ( len - 1 ) ; this . removeAt ( len - 1 , 1 ) ; return ret ; }