public function setFilenameSetsTheMediaType()
{
$resource = new PersistentResource();
$resource->setFilename('Something.jpg');
$this->assertSame('image/jpeg', $resource->getMediaType());
$resource->setFilename('Something.png');
$this->assertSame('image/png', $resource->getMediaType());
$resource->setFilename('Something.Jpeg');
$this->assertSame('image/jpeg', $resource->getMediaType());
}