public function testSetFunction()
{
$this->if($call = new testedClass())->then->object($call->setFunction($function = uniqid()))->isIdenticalTo($call)->string($call->getFunction())->isEqualTo($function)->object($call->setFunction('foo'))->isIdenticalTo($call)->string($call->getFunction())->isEqualTo('foo')->object($call->setFunction('FOo'))->isIdenticalTo($call)->string($call->getFunction())->isEqualTo('FOo');
}