//Ping Pong Expression
//This expression allow your to loop back and forth 2 keyframes also called boomerang expression.
//You can use either loopIn(“pingpong”) or loopOut(“pingpong”)

loopIn() 
This expression allow you  to loop anything before the first keyframe.

loopOut()
This expression allow you  to loop anything after the last keyframe.

loopOut('pingpong')
This expression allow your to loop back and forth 2 keyframes also called boomerang expression.
You can use either loopIn(“pingpong”) or loopOut(“pingpong”)

loopOut('continue')
The loopOut('continue') expression use the last keyframe to continue its direction and speed until the end of your timeline. This expression should be helpful if you want a layer to travel over time.

loopOut('cycle')
The loop cycle expression is basically the default value, when you write loopOut(“cycle”) it is the same as writing loopOut().
This expression can be more useful if you use an argument modifier.

loopOut('offset')
The loop offset expression allow your to repeat the first or last keyframe or offset the path overtime
