undo method Null safety
Takeback the last half-move, returning a move Map if successful, otherwise null.
Implementation
Map<String, dynamic>? undo() {
final move = undo_move();
return (move != null) ? make_pretty(move) : null;
}
Takeback the last half-move, returning a move Map if successful, otherwise null.
Map<String, dynamic>? undo() {
final move = undo_move();
return (move != null) ? make_pretty(move) : null;
}