public function testCopyPrivatePropertyFromSubClassObject()
{
$obj1 = new SubClass();
$obj1->setPrivateProperty('Modified private property value of BaseClass');
$obj2 = new BaseClass();
$obj2->copyPrivateProperty($obj1);
$this->assertEquals('Modified private property value of BaseClass', $obj2->getPrivateProperty());
$obj3 = new SubClass();
$obj3->copyPrivateProperty($obj1);
$this->assertEquals('Modified private property value of BaseClass', $obj3->getPrivateProperty());
}