Draws a filled or stroked circle

@param {String} args The arguments to the command
function CircleCommand(args) {
    var parsed = new statements.ArgumentStatement(args);

    if (parsed.args.length < 3) throw new SyntaxError('CIRCLE command requires 3 arguments');
    this.x = parsed.args[0];
    this.y = parsed.args[1];
    this.radius = parsed.args[2];
    this.stroke = parsed.args.length > 3 ? parsed.args[3] : false;
}