protected void RemovePiece(Position from, IGameState state)
{
state.NewEmptyPiece(from);
}
protected void RollbackMovePiece(Position from, Position to, IGameState state)
{
state[from] = state[to];
state[from].Unmove();
state.NewEmptyPiece(to);
}
protected void MovePiece(Position from, Position to, IGameState state)
{
state[to] = state[@from];
state[to].Move(to);
state.NewEmptyPiece(from);
}