Method add

lib/array-set.js:46–55

* Add the given string to this set. * * @param String aStr

(aStr, aAllowDuplicates)

   * @param String aStr
   */
  add(aStr, aAllowDuplicates) {
    const isDuplicate = this.has(aStr);
    const idx = this._array.length;
    if (!isDuplicate || aAllowDuplicates) {
      this._array.push(aStr);
    }
    if (!isDuplicate) {
      this._set.set(aStr, idx);
    }
  }

  /**
   * Is the given string a member of this set?