Could you tell me what the animationTimeMillis() in line 20 does?

Ah sry forgot to add this. i copied it from here https://github.com/alexjlockwood/bees-and-bombs-compose/blob/master/app/src/main/java/com/alexjlockwood/beesandbombs/demos/utils/AnimationUtils.kt It recomposes with an increasing value. Will add the link to the gist

Thank you，i think i got it😀