public function main()
{
$piece = new Piece(new StateTwo());
//Starts on One
$piece->moveDown();
//Goes to Three
$piece->moveRight();
//Goes to Four
$piece->moveUp();
//Goes to Two
$piece->moveLeft();
//Goes to One
$piece->moveLeft();
//Error
$piece->moveLeft();
//Error
$piece->moveUp();
//Error
$piece->moveRight();
//Goes to Two
$piece->moveUp();
//Error
}
