code: func (c *Animation) SetPlaybackRate(playbackRate float64) (*gcdmessage.ChromeResponse, error) {
  	var v AnimationSetPlaybackRateParams
  	v.PlaybackRate = playbackRate
  	return c.SetPlaybackRateWithParams(&v)
  }
docs: // SetPlaybackRate - Sets the playback rate of the document timeline.
  // playbackRate - Playback rate for animations on page