✅ Custom concurrency.
✅ Events for task addition, idle state change,
done callback firing.
✅ Programmatic and automatic start.
✅ Different kinds of addition and removal.
❌ Priority value for each task.
❌ Storing tasks as a map of priorities.
❌ Adding/removing tasks to/from an existing priority.
❌ Adding/removing multiple tasks to/from an existing priority.
❌ Adding tasks to a new priority.
❌ Adding multiple tasks to a new priority.
❌ Removal of a priority.