code: func List(c *messagebird.Client, options *ListOptions) (*GroupList, error) {
  	query, err := listQuery(options)
  	if err != nil {
  		return nil, err
  	}
  
  	groupList := &GroupList{}
  	if err := c.Request(groupList, http.MethodGet, path+"?"+query, nil); err != nil {
  		return nil, err
  	}
  
  	return groupList, nil
  }
docs: // List retrieves a paginated list of groups, based on the options provided.
  // It's worth noting DefaultListOptions.