constructor(requestBundles, createContext, name, observer) {
    super(requestBundles, createContext);

    this.name = name;
    this.query = `[data-l10n-with=${name}]`;
    this.roots = new Set();
    this.observer = observer;
  }
@param   {Function}             requestBundles
@param   {Function}             createContext
@param   {string}               name
@param   {DocumentLocalization} [observer]
@returns {DOMLocalization}