Condition if the mouse arrow is moving

Hello, how do I make a condition if the mouse arrow is moving? Because the machine gun on my ship rotates at an angle according to the mouse, but I want that when the mouse is stopped, the machine gun rotates back to the standard angle, instead of always following the arrow of the mouse. I just want you to follow the mouse arrow if the mouse is moving.

Here is a demo

dropbox.com/s/excarirjjkjgfn3/GunRotateToMouse.c3p

Thank you very much for responding with a practical example, thank you for taking the time, that was incredible. It works perfectly, that's exactly what I wanted. Thank you very much.