How to use the raf function in raf

raf(callback) {
        if (this.requestFrame) raf.cancel(this.requestFrame);
        this.requestFrame = raf(() => {
            this.requestFrame = undefined;
            callback();
        });
    }

public notifySubscribers(evt) {
    if (!this.framePending) {
      const {currentTarget} = evt;

      this.rafHandle = raf(() => {
        this.framePending = false;
        const {top, bottom} = this.node.getBoundingClientRect();

        this.subscribers.forEach(handler =>
          handler({
            distanceFromTop: top,
            distanceFromBottom: bottom,
            eventSource: currentTarget === window ? document.body : this.node
          })
        );
      });
      this.framePending = true;
    }
  }

function animate() {
      raf(animate)
      tween.update()
    }

handleTouchMove(e) {
    e.preventDefault();
    if (!this._updatingPosition) {
      const { clientX: x, clientY: y } = e.touches[0];
      raf(() => this._updatePosition({x, y}));
    }
    this._updatingPosition = true;
    this._clearHoldTimers();
  }

prepareTween() {
        this.tweenHandle = raf((timestamp) => {
            this.tweenValue(timestamp, true);
        });

    }

runLoop() {
    this.rafId = raf(this.loopBound);
  }

function slideLeftOut(action, component, done) {
  if (action === 'push') {
    raf(() => {
      component.setState({
        style: {
          transform: 'translate3d(0, 0, 0)',
          WebkitTransform: 'translate3d(0, 0, 0)',
          opacity: 1,
          zIndex: 1,
        },
      });
      raf(() => {
        component.setState({
          style: {
            transform: 'translate3d(-20%, 0, 0)',
            WebkitTransform: 'translate3d(-20%, 0, 0)',
            transition: 'all .4s cubic-bezier(.2, .7, .1, 1)',
            transitionProperty: 'transform, opacity',
            WebkitTransition: 'all .4s cubic-bezier(.2, .7, .1, 1)',

function animate () {
      raf(animate)
      tween.update()
    }

function animate() {
    raf(animate)
    if (tween) tween.update()
  }
  animate()

var frameFunc = function frameFunc() {
    var timestamp = Date.now();
    var time = timestamp - startTime;
    var nextScrollTop = easeInOutCubic(time, scrollTop, targetScrollTop, 450);

    if (container === window) {
      window.scrollTo(window.pageXOffset, nextScrollTop);
    } else {
      container.scrollTop = nextScrollTop;
    }

    if (time < 450) {
      raf(frameFunc);
    } else {
      callback();
    }
  };