This is a circle collider for the excalibur rigid body physics simulation
Position of the circle relative to the collider, by default (0, 0).
Get the radius of the circle
Set the radius of the circle
Returns a clone of this shape, not associated with any collider
Tests if a point is contained in this collider
Returns the moment of inertia of a circle given it's mass https://en.wikipedia.org/wiki/List_of_moments_of_inertia
Updates collider world space geometry