public function testTransportedPayloadManipulation()
 {
     $transport = new AuthenticationTransport($this->token_bearer_adapter, $this->user, $this->token);
     $this->assertNull($transport->getPayload());
     $new_payload = [1, 2, 3];
     $transport->setPayload($new_payload);
     $this->assertSame($new_payload, $transport->getPayload());
 }