code: func (s *HTTPServer) SessionList(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
  	args := structs.DCSpecificRequest{}
  	if done := s.parse(resp, req, &args.Datacenter, &args.QueryOptions); done {
  		return nil, nil
  	}
  
  	var out structs.IndexedSessions
  	defer setMeta(resp, &out.QueryMeta)
  	if err := s.agent.RPC("Session.List", &args, &out); err != nil {
  		return nil, err
  	}
  
  	// Use empty list instead of nil
  	if out.Sessions == nil {
  		out.Sessions = make(structs.Sessions, 0)
  	}
  	return out.Sessions, nil
  }
docs: // SessionList is used to list all the sessions