private bool IsLegalEnPassant(Square[][] board, Move move, IEnumerable<Move> pastMoves)
{
if (pastMoves == null) return false;
var lastMove = pastMoves.LastOrDefault();
if (lastMove == null) return false;
var piece = GetDestinationPiece(board, lastMove);
if (IsPawnsSecondMoveInProperDirection(move, lastMove, piece))
{
return true;
}
return false;
}