SparkPost\SparkPostResponse::withBody PHP Метод

    public function withBody(StreamInterface $body)
    {
        return $this->response->withBody($body);
    }

 public function testWithBody()
 {
     $param = Mockery::mock('Psr\\Http\\Message\\StreamInterface');
     $this->responseMock->shouldReceive('withBody')->andReturn($this->returnValue);
     $sparkpostResponse = new SparkPostResponse($this->responseMock);
     $this->assertEquals($this->responseMock->withBody($param), $sparkpostResponse->withBody($param));
 }