src/lib/collections/list.js
function (index, collection) {
        assertType(index, Number);
        assertNotNull(collection);

        if (index !== this.length) {
            validateListIndex(this, index);
        }

        var arr = buffer(collection),
            count = arr.length,
            len = this.length + count;

        this.length = len;

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

        while (count-- > 0) {
            this[index + count] = arr[count];
        }
    }
function (index, collection) {
        assertType(index, Number);
        assertNotNull(collection);

        if (index !== this.length) {
            validateListIndex(this, index);
        }

        var arr = buffer(collection),
            count = arr.length,
            len = this.length + count;

        this.length = len;

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

        while (count-- > 0) {
            this[index + count] = arr[count];
        }
    }
function ( index , collection ) { assertType ( index , Number ) ; assertNotNull ( collection ) ; if ( index !== this . length ) { validateListIndex ( this , index ) ; } var arr = buffer ( collection ) , count = arr . length , len = this . length + count ; this . length = len ; while ( len -- > index ) { this [ len ] = this [ len - count ] ; } while ( count -- > 0 ) { this [ index + count ] = arr [ count ] ; } }
Inserts the elements of a collection into the List at the specified index.
@param {Number} index The zero-based index at which item should be inserted.
@param {Iterable} collection The collection whose elements should be inserted into the List.
Inserts the elements of a collection into the List at the specified index .