A CirclePath2D defines a circular path on which a PathFollower can be placed, making it simple to tween objects
along a circle or oval (make an oval by altering the width/height/scaleX/scaleY properties).
Constants for defining the direction in which to travel on a MotionPath (like
CLOCKWISE, COUNTER_CLOCKWISE, SHORTEST, etc.).
A LinePath2D defines a path (using as many Points as you want) on which a PathFollower can be
placed and animated.
A MotionPath defines a path along which a PathFollower can travel, making it relatively simple to do
things like tween an object in a circular path.
A PathFollower is used to associate a particular target object (like a MovieClip, Point, Sprite, etc.)
with a MotionPath and it offers a tweenable
progress property that manages positioning
the target on the path accordingly.
A RectanglePath2D defines a rectangular path on which a PathFollower can be placed, making it simple to tween objects
along a rectangle's perimeter.