public function test_set_post_date() { $r = self::factory()->response->create(); $response = new \WeBWorK\Server\Response($r); $new_date = '2015-05-05 05:05:05'; $response->set_post_date($new_date); $this->assertTrue($response->save()); $response2 = new \WeBWorK\Server\Response($r); $this->assertSame($new_date, $response2->get_post_date()); }