Method constructor

src/service/variable-source.js:164–175

* @param {!./ampdoc-impl.AmpDoc} ampdoc

(ampdoc)

   * @param {!./ampdoc-impl.AmpDoc} ampdoc
   */
  constructor(ampdoc) {
    /** @protected @const {!./ampdoc-impl.AmpDoc} */
    this.ampdoc = ampdoc;

    /** @private @const {!{[key: string]: !ReplacementDef}} */
    this.replacements_ = Object.create(null);

    /** @private {boolean} */
    this.initialized_ = false;

    this.getUrlMacroAllowlist_();
  }

  /**
   * Lazily initialize the default replacements.