code: func (fb *Firebase) IncludePriority(v bool) {
  	fb.paramsMtx.Lock()
  	if v {
  		fb.params.Set(formatParam, formatVal)
  	} else {
  		fb.params.Del(formatParam)
  	}
  	fb.paramsMtx.Unlock()
  }
docs: // IncludePriority determines whether or not to ask Firebase
  // for the values priority. By default, the priority is not returned.
  //
  // Reference https://www.firebase.com/docs/rest/api/#section-param-format