private void Left_Click(object sender, EventArgs e)
 {
     MovePiece?.Invoke(Direction.left);
 }
 private void Right_Click(object sender, EventArgs e)
 {
     MovePiece?.Invoke(Direction.right);
 }
 private void Up_Click(object sender, EventArgs e)
 {
     MovePiece?.Invoke(Direction.up);
 }
 private void Down_Click(object sender, EventArgs e)
 {
     MovePiece?.Invoke(Direction.down);
 }