append(new EntityDouble('test', 23, new \DateTime('now', new \DateTimeZone('UTC')), 'privTest')); $collection->append(new EntityDouble('test2', 25, new \DateTime('now', new \DateTimeZone('UTC')), 'privTest23')); self::assertEquals(['test', 'test2'], $collection->column('protString')); self::assertEmpty($collection->column('privString')); self::assertEquals([23,25], $collection->column('protInt')); } }