https://github.com/facebook/react/blob/30b47103d4354d9187dc0f1fb804855a5208ca9f/packages/scheduler/src/Scheduler.js#L180-L185
it('cancels a delayed task', () => {
      
      const options = {delay: 100};
      scheduleCallback(
        NormalPriority,
        () => Scheduler.unstable_yieldValue('A'),
        options,
      );
      const taskB = scheduleCallback(
        NormalPriority,
        () => Scheduler.unstable_yieldValue('B'),
        options,
      );
      const taskC = scheduleCallback(
        NormalPriority,
        () => Scheduler.unstable_yieldValue('C'),
        options,
      );
      
      expect(Scheduler).toFlushAndYield([]);
      cancelCallback(taskB);
      
      Scheduler.unstable_advanceTime(500);
      cancelCallback(taskC);
      
      expect(Scheduler).toFlushAndYield(['A']);
    });
  });
});