Inheritance: extends AbstractUploader
 public function testUploadsData()
 {
     $requestWrapper = $this->prophesize('Google\\Cloud\\RequestWrapper');
     $stream = Psr7\stream_for('abcd');
     $successBody = '{"canI":"kickIt"}';
     $response = new Response(200, [], $successBody);
     $requestWrapper->send(Argument::type('Psr\\Http\\Message\\RequestInterface'), Argument::type('array'))->willReturn($response);
     $uploader = new MultipartUploader($requestWrapper->reveal(), $stream, 'http://www.example.com');
     $this->assertEquals(json_decode($successBody, true), $uploader->upload());
 }