public splice(start: number, deleteCount?: number, ...items: T[]): T[] {
let itemsRemoved: T[];
- if (arguments.length >= 3 && typeof deleteCount !== 'undefined') {
+ if (arguments.length >= 3 && deleteCount !== undefined) {
itemsRemoved = super.splice(start, deleteCount);
// FIXME: that makes the items insert not in place
this.push(...items);