Is it possible to play an animation in reverse using the starling runtime?

Thanks BinaryCats. I can control the speed of the spine skeleton animation "heroWalking" by doing:
"heroWalking.timeScale = .5;" but "heroWalking.timeScale = -1;" just freezes the animation.

Here's Spine's explanation. http://esotericsoftware.com/spine-using-runtimes#Applying-animations

Still trying to figure out how to implement it in the Starling Spine runtime.