code: func (c *Client) UpdateSession(req session.UpdateRequest) error {
  	if err := req.Check(); err != nil {
  		return trace.Wrap(err)
  	}
  	_, err := c.PutJSON(c.Endpoint("namespaces", req.Namespace, "sessions", string(req.ID)), updateSessionReq{Update: req})
  	return trace.Wrap(err)
  }
docs: // UpdateSession updates existing session