class Task { final int id; String title; String? desc; DateTime? dueDate; DateTime? scheduleDate; bool isCompleted; Priority priority; String? category; DateTime createTime; Task({ int? id, required this.title, this.desc, this.dueDate, this.scheduleDate, this.isCompleted = false, this.priority = Priority.medium, this.category, DateTime? createTime, }) : id = id ?? DateTime.timestamp().microsecond, createTime = DateTime.now(); } enum Priority { low, medium, high }