public function testToCommandString()
{
$expected = 'callback function code';
$callback = $this->getMockBuilder('\\Clinner\\Command\\Callback')->disableOriginalConstructor()->setMethods(array('getCallbackCode'))->getMock();
$callback->expects($this->once())->method('getCallbackCode')->will($this->returnValue($expected));
$result = $callback->toCommandString();
$this->assertEquals($expected, $result);
}