1/**
 2 * Uses in .map to peek-count when iterating.
 3 */
 4export class Counter<T> {
 5  private counter = 0;
 6
 7  count(t: T) {
 8    this.counter++;
 9    return t;
10  }
11
12  getCount(): number {
13    return this.counter;
14  }
15}