methodCalled(methodName, opt_arg) {
    const methodData = this.resolverMap_.get(methodName);
    methodData.callCount += 1;
    this.resolverMap_.set(methodName, methodData);
    methodData.resolver.resolve(opt_arg);
  }
/**
   * Called by subclasses when a tracked method is called from the code that
   * is being tested.
   * @param {string} methodName
   * @param {*=} opt_arg Optional argument to be forwarded to the testing
   *     code, useful for checking whether the proxy method was called with
   *     the expected arguments.
   * @protected
   */
Called by subclasses when a tracked method is called from the code that
is being tested.
@param {string} methodName
@param {*=} opt_arg Optional argument to be forwarded to the testing
code, useful for checking whether the proxy method was called with
the expected arguments.
@protected
Called by subclasses when a tracked method is called from the code that is being tested . @param { string } methodName @param { * = } opt_arg Optional argument to be forwarded to the testing code useful for checking whether the proxy method was called with the expected arguments . @protected
methodCalled(methodName, opt_arg) {
    const methodData = this.resolverMap_.get(methodName);
    methodData.callCount += 1;
    this.resolverMap_.set(methodName, methodData);
    methodData.resolver.resolve(opt_arg);
  }
methodCalled ( methodName , opt_arg ) { const methodData = this . resolverMap_ . get ( methodName ) ; methodData . callCount += 1 ; this . resolverMap_ . set ( methodName , methodData ) ; methodData . resolver . resolve ( opt_arg ) ; }
Called by subclasses when a tracked method is called from the code that
 is being tested.
Called by subclasses when a tracked method is called from the code that is being tested .