code: func (s *APIServer) postSessionSlice(auth ClientI, w http.ResponseWriter, r *http.Request, p httprouter.Params, version string) (interface{}, error) {
  	data, err := ioutil.ReadAll(r.Body)
  	if err != nil {
  		return nil, trace.Wrap(err)
  	}
  	var slice events.SessionSlice
  	if err := slice.Unmarshal(data); err != nil {
  		return nil, trace.BadParameter("failed to unmarshal %v", err)
  	}
  	if err := auth.PostSessionSlice(slice); err != nil {
  		return nil, trace.Wrap(err)
  	}
  	return message("ok"), nil
  }
docs: // HTTP POST /:version/sessions/:id/slice