How to use the scheduler.unstable_IdlePriority function in scheduler

square = () => {
    // facebook/react#13488 seems to imply deferredUpdates is no longer necessary
    // Also see note in changelog: facebook/react#13571
    scheduler.unstable_scheduleCallback(scheduler.unstable_IdlePriority, () =>
      this.setState(prevState => ({
        values: prevState.values.map(value => value * value)
      }))
    );
  };

addChild = () => {
    scheduler.unstable_scheduleCallback(scheduler.unstable_IdlePriority, () =>
      this.setState(prevState => ({
        values: [...prevState.values, prevState.values.length + 1]
      }))
    );
  };