如何在Qt中使用QUndoCommand

Hello guys I am working on a graphics editor in which I transform QGraphicsItem using 3 different QSliders for scale, rotate Z-axis and rotate X or Y-axis. So how can I use QUndoCommand to achive it. I was reading documentation Push is used for pushing on the stack by which redo gets called. What is mergewith method and how can I use it if I it is used for my concern. Any help will be appreciated.Hello guys I am working on a graphics editor in