public function testReadNextReturnNullIfThereIsNoData()
 {
     $httpResponse = $this->getMock('GuzzleHttp\\Message\\ResponseInterface');
     $this->iterator->expects($this->once())->method('valid')->willReturn(true);
     $this->iterator->expects($this->once())->method('current')->willReturn($httpResponse);
     $httpResponse->expects($this->once())->method('json')->willReturn([]);
     $this->assertNull($this->invokeMethod($this->instance, 'readNext'));
 }
 /**
  * {@inheritdoc}
  */
 public function rewind()
 {
     $this->iterator->rewind();
     parent::rewind();
 }