Note: animator.ease() can be used to make rocking animations by letting percent go from 0 to 2 instead of 0 to 1.
This is a read only value, and contains the number of milliseconds since the operating system was started (you can use it to check uptime).
It's usually used to determine how many milliseconds into an animation you are.
function animator.runUntilDone([animation | array]);
You can pass either a single animation or an array of them into this function. runUntilDone() will not return until all animations you passed to it are complete. In general, you should use animator.start() to run animations asynchronously, as they won't block user input while they are running.
function animator.start([animation | array]);
This is a read only value, and doesn't really exist until the animation is actually started. You can then use it in an animation callback for a custom animation to see how far into your animation you are. The delta will be animator.milliseconds - this.startTime.