public function testToWebFormatWithSetAttachmentAndCid()
{
$email = new Email();
$email->setAttachment('./gif.gif', null, 'sample-cid');
$json = $email->toWebFormat();
$this->assertEquals($json["files[gif.gif]"], "@./gif.gif");
$this->assertEquals($json["content[gif.gif]"], "sample-cid");
}