errFatal(local.RegisterSingleHandler(handlerTest, func(payload []byte) ([]byte, *RemoteErr) {
		t.Log("1: server payload: ", len(payload), "bytes.")
		return append([]byte{}, payload...), nil
	}))
	// 2: Return as error
	errFatal(local.RegisterSingleHandler(handlerTest2, func(payload []byte) ([]byte, *RemoteErr) {
		t.Log("2: server payload: ", len(payload), "bytes.")
		err := RemoteErr(payload)
		return nil, &err
	}))

	remote := grid.Managers[1]

func NewRemoteErrString(msg string) *RemoteErr {
	r := RemoteErr(msg)
	return &r
}

func (r RemoteErr) Error() string {
	return string(r)
}

// Is returns if the string representation matches.
func (r *RemoteErr) Is(other error) bool {
	if r == nil || other == nil {
		return r == other
	}
	var o RemoteErr
	if errors.As(other, &o) {
		return r == &o
	}

	errFatal(local.RegisterSingleHandler(handlerTest, func(payload []byte) ([]byte, *RemoteErr) {
		t.Log("1: server payload: ", len(payload), "bytes.")
		return append([]byte{}, payload...), nil
	}))
	// 2: Return as error
	errFatal(local.RegisterSingleHandler(handlerTest2, func(payload []byte) ([]byte, *RemoteErr) {
		t.Log("2: server payload: ", len(payload), "bytes.")
		err := RemoteErr(payload)
		return nil, &err
	}))

The server handler function has this signature: `type SingleHandlerFn func(payload []byte) ([]byte, *RemoteErr)`.

Sample handler:
```go
    handler :=  func(payload []byte) ([]byte, *grid.RemoteErr) {
        // Do something with payload
        return []byte("response"), nil
    }

    err := manager.RegisterSingleHandler(grid.HandlerDiskInfo, handler)
```

	start := time.Now()
	defer func() {
		if debugPrint {
			fmt.Println("Mux", m.ID, "Handler took", time.Since(start).Round(time.Millisecond))
		}
		if r := recover(); r != nil {
			gridLogIf(ctx, fmt.Errorf("grid handler (%v) panic: %v", msg.Handler, r))
			err := RemoteErr(fmt.Sprintf("handler panic: %v", r))
			handlerErr = &err
		}

		// Register a single handler which echos the payload.
		errFatal(remote.RegisterSingleHandler(handlerTest, func(payload []byte) ([]byte, *RemoteErr) {
			defer PutByteBuffer(payload)
			return append(GetByteBuffer()[:0], payload...), nil
		}))
		errFatal(rpc.Register(remote, func(req *testRequest) (resp *testResponse, err *RemoteErr) {
			return &testResponse{
				OrgNum:    req.Num,
				OrgString: req.String,
				Embedded:  *req,
			}, nil
		}))

		}
		PutByteBuffer(m.Payload)
		return
	}
	if m.Flags&FlagPayloadIsErr != 0 {
		v.response(m.Seq, Response{
			Msg: nil,
			Err: RemoteErr(m.Payload),
		})
		if v.cancelFn != nil {
			v.cancelFn(RemoteErr(m.Payload))
		}
		PutByteBuffer(m.Payload)
		v.close()
		c.outgoing.Delete(m.MuxID)
		return
	}
	// Return payload.
	if m.Payload != nil {

	"github.com/gobwas/ws"
	"github.com/gobwas/ws/wsutil"
	"github.com/minio/minio/internal/bpool"
)

// ErrDisconnected is returned when the connection to the remote has been lost during the call.
var ErrDisconnected = RemoteErr("remote disconnected")

const (
	// minBufferSize is the minimum buffer size.
	// Buffers below this is not reused.
	minBufferSize = 1 << 10

	// defaultBufferSize is the default buffer allocation size.

	ok := m.addResponse(r)
	if !ok {
		PutByteBuffer(r.Msg)
	}
}

var errStreamEOF = errors.New("stream EOF")

// error is a message from the server to disconnect.
func (m *muxClient) error(err RemoteErr) {
	if debugPrint {
		fmt.Printf("mux %d: got remote err:%v\n", m.MuxID, string(err))
	}
	m.addResponse(Response{Err: &err})
}

func (m *muxClient) ack(seq uint32) {
	if !m.checkSeq(seq) {
		return

// To abstract a node over network.
type lockRESTServer struct {
	ll *localLocker
}

// RefreshHandler - refresh the current lock
func (l *lockRESTServer) RefreshHandler(args *dsync.LockArgs) (*dsync.LockResp, *grid.RemoteErr) {
	// Add a timeout similar to what we expect upstream.
	ctx, cancel := context.WithTimeout(context.Background(), dsync.DefaultTimeouts.RefreshCall)
	defer cancel()

	resp := lockRPCRefresh.NewResponse()