code: func (c *Client) ServerGroups() ([]ServerGroup, error) {
  	var groups []ServerGroup
  	_, err := c.MakeApiRequest("GET", "/1.0/server_groups", nil, &groups)
  	if err != nil {
  		return nil, err
  	}
  	return groups, err
  }
docs: // ServerGroups retrieves a list of all server groups