lua.wetgenes.gamecake.zone.scene.values.get
value=values:get(key)
value=values:get(key,topidx)
Get the current value for this key by searching from the top of the stack to the bottom and returning the first non nil value we find.
If topidx is given then get the value at this idx, this would normally be negative in which it counts back from the end. So it is easy to time travel back a frame into the cached values with -1 as the idx.