(conf0)  if err != nil {   t.Fatalf("err: %v", err)  }  defer os.RemoveAll(dir0)  defer c0.Shutdown()   // Try an RPC  var out struct{}  if err := c0.RPC("Status.Ping", struct{}{}, &out); err != structs.ErrNoServers {   t.Fatalf("err: %v", err)  }   // Try to join  addr := fmt.Sprintf("000.0.0.0:%d",   s0.config.SerfLANConfig.MemberlistConfig.BindPort)  if _, err := c0.JoinLAN([]string{addr}); err != nil {   t.Fatalf("err: %v", err)  }   // Check the members  if len(s0.LANMembers()) != 0 {   t.Fatalf("bad len")  }   if len(c0.LANMembers()) != 0 {   t.Fatalf("bad len")  }   // RPC should succeed  testutil.WaitForResult(func() (bool, error) {   err := c0.RPC("Status.Ping", struct{}{}, &out)   return err == nil, err  }, func(err error) {   t.Fatalf("err: %v", err)  }) }  func TestClient