code: func (c *Client) GetUsers() ([]services.User, error) {
  	out, err := c.Get(c.Endpoint("users"), url.Values{})
  	if err != nil {
  		return nil, trace.Wrap(err)
  	}
  	var items []json.RawMessage
  	if err := json.Unmarshal(out.Bytes(), &items); err != nil {
  		return nil, trace.Wrap(err)
  	}
  	users := make([]services.User, len(items))
  	for i, userBytes := range items {
  		user, err := services.GetUserMarshaler().UnmarshalUser(userBytes, services.SkipValidation())
  		if err != nil {
  			return nil, trace.Wrap(err)
  		}
  		users[i] = user
  	}
  	return users, nil
  }
docs: // GetUsers returns a list of usernames registered in the system