function (delta) {
            var choices = this.findHighlightableChoices(),
                index = this.highlight();

            while (index > -1 && index < choices.length) {
                index += delta;
                var choice = $(choices[index]);
                if (choice.hasClass("select2-result-selectable") && !choice.hasClass("select2-disabled") && !choice.hasClass("select2-selected")) {
                    this.highlight(index);
                    break;
                }
            }
        }
function (delta) {
            var choices = this.findHighlightableChoices(),
                index = this.highlight();

            while (index > -1 && index < choices.length) {
                index += delta;
                var choice = $(choices[index]);
                if (choice.hasClass("select2-result-selectable") && !choice.hasClass("select2-disabled") && !choice.hasClass("select2-selected")) {
                    this.highlight(index);
                    break;
                }
            }
        }
function ( delta ) { var choices = this . findHighlightableChoices ( ) , index = this . highlight ( ) ; while ( index > - 1 && index < choices . length ) { index += delta ; var choice = $ ( choices [ index ] ) ; if ( choice . hasClass ( "select2-result-selectable" ) && ! choice . hasClass ( "select2-disabled" ) && ! choice . hasClass ( "select2-selected" ) ) { this . highlight ( index ) ; break ; } } }
abstract
abstract