Draws a custom shape

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

    if (parsed.args.length < 3) throw new SyntaxError('SHAPE command requires 3 arguments');
    this.pointsLength = parsed.args[0];
    this.pointsX = parsed.args[1];
    this.pointsY = parsed.args[2];
    this.stroke = parsed.args.length > 3 ? parsed.args[3] : false;
}