code: func (a *Agent) MembersOpts(opts MembersOpts) ([]*AgentMember, error) {
  	r := a.c.newRequest("GET", "/v1/agent/members")
  	r.params.Set("segment", opts.Segment)
  	if opts.WAN {
  		r.params.Set("wan", "1")
  	}
  
  	_, resp, err := requireOK(a.c.doRequest(r))
  	if err != nil {
  		return nil, err
  	}
  	defer resp.Body.Close()
  
  	var out []*AgentMember
  	if err := decodeBody(resp, &out); err != nil {
  		return nil, err
  	}
  	return out, nil
  }
docs: // MembersOpts returns the known gossip members and can be passed
  // additional options for WAN/segment filtering.