public function test_successful_save_for_new_item()
 {
     $response = new \WeBWorK\Server\Response();
     $response->set_content('foo');
     $response->set_question_id(20);
     $response->set_is_answer(false);
     $saved = $response->save();
     $this->assertTrue($saved);
     $new_response = new \WeBWorK\Server\Response($response->get_id());
     $this->assertSame('foo', $new_response->get_content());
     $this->assertSame(20, $new_response->get_question_id());
     $this->assertFalse($new_response->get_is_answer());
 }