TestFormWithPredefinedForm example

$form = $this->formBuilder->buildForm($form_id, $form_state);
    $this->assertFormElement($expected_form, $form, 'test');
    $this->assertSame('test-form', $form['#id']);
  }

  /** * @covers ::buildForm * * @dataProvider providerTestChildAccessInheritance */
  public function testChildAccessInheritance($element, $access_checks) {
    $form_arg = new TestFormWithPredefinedForm();
    $form_arg->setForm($element);

    $form_state = new FormState();

    $form = $this->formBuilder->buildForm($form_arg, $form_state);

    $actual_access_structure = [];
    $expected_access_structure = [];

    // Ensure that the expected access checks are set.     foreach ($access_checks as $access_check) {