class TaskAssignment { TaskAssignment({ required this.taskId, required this.userId, required this.createdAt, }); final String taskId; final String userId; final DateTime createdAt; factory TaskAssignment.fromMap(Map map) { return TaskAssignment( taskId: map['task_id'] as String, userId: map['user_id'] as String, createdAt: DateTime.parse(map['created_at'] as String), ); } }