public function testCanNotSendASecondResponse()
{
$service = $this->createService();
$response = $service->prepareResponse('foo');
ob_start();
$sent_response = $service->send($response);
ob_get_clean();
$this->assertInstanceOf(Response::class, $sent_response);
$response2 = $service->prepareResponse('bar');
$this->assertEquals($response, $service->send($response2));
}