findFrom method
Implementation
SquarePosition? findFrom(String piece) {
if (last == null) {
return null;
}
for (var rank in board.entries) {
for (var file in rank.value.entries) {
if (file.value.piece == "" && last!.board[rank.key]![file.key]!.piece == piece) {
return SquarePosition(rank.key, file.key);
}
}
}
return null;
}