Implement a Dependency-Aware Task Scheduler

Implement a `TaskManager` class with two methods: - `AddTasks(tasks)`: add one or more tasks into the system. - `ConsumeTask()`: return and remove the executable task with the earliest deadline. Each task has the following fields: - `id`: unique task identifier - `ddl`: integer deadline, where a smaller value means an earlier deadline - `subTasks`: a list of prerequisite task IDs that must be completed before this task can be consumed Requirements: 1. Support multiple calls to `AddTasks`. 2. `ConsumeTask()` should return the pending task with the smallest deadline among all currently executable tasks. 3. A task is executable only if all of its prerequisite tasks have already been consumed. 4. If no executable task exists, return `NO_TASK`. 5. For this coding problem, assume task IDs are unique and the dependency graph is valid and acyclic. Explain the data structures you would use and implement both methods efficiently.