GetSize = function (rect, out) {
    if (out === undefined) { out = new Point(); }

    out.x = rect.width;
    out.y = rect.height;

    return out;
}
The size of the Rectangle object, expressed as a Point object
 with the values of the width and height properties.

@function Phaser.Geom.Rectangle.GetSize
@since 3.0.0

@generic {Phaser.Geom.Point} O - [out,$return]

@param {Phaser.Geom.Rectangle} rect - [description]
@param {(Phaser.Geom.Point|object)} [out] - [description]

@return {(Phaser.Geom.Point|object)} [description]