text: declare function raf(callback: (timestamp: number) => void): AnimationFrameID;
  
  // TODO: would like to use `import type {Stub} from 'raf-stub'
  // This is not supported right now: https://github.com/flow-typed/flow-typed/issues/2023
  declare var requestAnimationFrame: {
    add: (cb: Function) => number,
    remove: (id: number) => void,
    flush: (duration?: number) => void,
    reset: () => void,
    step: (steps?: number, duration?: number) => void,
  } & typeof raf;
  