https://github.com/facebook/react/blob/30b47103d4354d9187dc0f1fb804855a5208ca9f/packages/scheduler/src/Scheduler.js#L180-L185
/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 */
import {
  enableSchedulerDebugging,
  enableProfiling,
} from './SchedulerFeatureFlags';
import {
  requestHostCallback,
  requestHostTimeout,
  cancelHostTimeout,
  shouldYieldToHost,
  getCurrentTime,
  forceFrameRate,
  requestPaint,
} from './SchedulerHostConfig';
import {push, pop, peek} from './SchedulerMinHeap';
import {
  ImmediatePriority,
  UserBlockingPriority,
  NormalPriority,
  LowPriority,
  IdlePriority,