UUID = function ()
{
    return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function (c)
    {
        var r = Math.random() * 16 | 0;
        var v = (c === 'x') ? r : (r & 0x3 | 0x8);

        return v.toString(16);
    });
}
Creates and returns an RFC4122 version 4 compliant UUID.

The string is in the form: `xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx` where each `x` is replaced with a random
hexadecimal digit from 0 to f, and `y` is replaced with a random hexadecimal digit from 8 to b.

@function Phaser.Utils.String.UUID
@since 3.12.0

@return {string} The UUID string.