/**
  * @covers ::addMapping
  * @covers ::getImageStyle
  */
 public function testGetImageStyle()
 {
     $entity = new ResponsiveImageMapping(array(''));
     $entity->addMapping('test_breakpoint', '1x', 'test_style');
     $this->assertEquals('test_style', $entity->getImageStyle('test_breakpoint', '1x'));
     $this->assertNull($entity->getImageStyle('test_unknown_breakpoint', '1x'));
 }