public function testChangeElementKey()
 {
     $a['#type'] = 'textfield';
     $a['#form_builder'] = array('element_id' => 'A');
     $form_obj = new FormBuilderFormBase('webform', 'test', NULL, array(), array('a' => $a));
     $a['#key'] = 'b';
     $form_obj->setElementArray($a);
     $form = $form_obj->getFormArray();
     $this->assertArrayHasKey('b', $form);
     $this->assertArrayNotHasKey('a', $form);
 }