nl_tokens: Removes the last element from the set and returns it or null if it s empty .
pl_tokens: function ( ) { if ( get ( this , 'isFrozen' ) ) throw new Ember . Error ( Ember . FROZEN_ERROR ) ; var obj = this . length > 0 ? this [ this . length - 1 ] : null ; this . <mask> ( obj ) ; return obj ; }