src/lib/collections/list.js
function (index, item) {
        if (index !== this.length) {
            validateListIndex(this, index);
        }

        var len = ++this.length;

        while (len-- > index) {
            this[len] = this[len - 1];
        }

        this[index] = item;
    }
function (index, item) {
        if (index !== this.length) {
            validateListIndex(this, index);
        }

        var len = ++this.length;

        while (len-- > index) {
            this[len] = this[len - 1];
        }

        this[index] = item;
    }
function ( index , item ) { if ( index !== this . length ) { validateListIndex ( this , index ) ; } var len = ++ this . length ; while ( len -- > index ) { this [ len ] = this [ len - 1 ] ; } this [ index ] = item ; }
Inserts an element into the List at the specified index.
@param {Number} index The zero-based index at which item should be inserted.
@param {Object} item The object to insert.
Inserts an element into the List at the specified index .