public function testRotate()
{
$imageProcessor = $this->getMockBuilder('Magento\\Framework\\Image')->disableOriginalConstructor()->getMock();
$imageProcessor->expects($this->once())->method('rotate')->with(90)->will($this->returnValue(true));
$this->image->setImageProcessor($imageProcessor);
$result = $this->image->rotate(90);
$this->assertSame($this->image, $result);
}