Circumference = function (circle)
{
    return 2 * (Math.PI * circle.radius);
}
Returns the circumference of the given Circle.

@function Phaser.Geom.Circle.Circumference
@since 3.0.0

@param {Phaser.Geom.Circle} circle - The Circle to get the circumference of.

@return {number} The circumference of the Circle.