Method set

lib/utils.js:341–350

(key, value = null)

  // Set value, and return that value.  If value is null, then delete key.
  set(key, value = null) {
    this.rotate();
    delete this.previous[key];
    if (value != null) {
      return this.cache[key] = value;
    } else {
      delete this.cache[key];
      return null;
    }
  }

  get(key) {
    this.rotate();