b.Cleanup(grid.Cleanup)
	// Create n managers.
	for _, remote := range grid.Managers {
		// 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{

	var sub *subHandlerID
	if m.Payload == nil {
		m.Payload = GetByteBuffer()[:0]
	}
	h, err := m.UnmarshalMsg(b)
	if err != nil {
		return nil, nil, fmt.Errorf("read write: %v", err)
	}
	if len(m.Payload) == 0 && m.Flags&FlagPayloadIsZero == 0 {
		PutByteBuffer(m.Payload)
		m.Payload = nil
	}
	if m.Flags&FlagCRCxxh3 != 0 {
		const hashLen = 4

                        - key: payload
                        - key: iss
                        value:
                          stringMatch:
                            exact: rule[0]-from[0]-requestPrincipal[1]
                    - metadata:
                        filter: envoy.filters.http.jwt_authn
                        path:
                        - key: payload
                        - key: sub

 */
public class BuildEvent extends Message {
    private final Object payload;

    public BuildEvent(Object payload) {
        this.payload = payload;
    }

    public Object getPayload() {
        return payload;
    }

    @Override
    public String toString() {
        return getClass().getSimpleName() + "[event=" + payload + "]";
    }

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)
```

		t.Fatalf("errors happened when create: %v", err)
	}

	CheckUser(t, user, user)

	var user2 User
	DB.Preload("Account").Preload("Pets").Preload("Toys").Preload("Company").Preload("Manager").Preload("Team").Preload("Languages").Preload("Friends").Find(&user2, "id = ?", user.ID)
	CheckUser(t, user2, user)
}

func TestBulkCreateWithAssociations(t *testing.T) {
	users := []User{

  }

  fun assertTextMessage(payload: String?) {
    assertThat(nextEvent()).isEqualTo(Message(string = payload))
  }

  fun assertBinaryMessage(payload: ByteString?) {
    assertThat(nextEvent()).isEqualTo(Message(payload))
  }

  fun assertPing(payload: ByteString) {
    assertThat(nextEvent()).isEqualTo(Ping(payload))
  }

  fun assertPong(payload: ByteString) {

    now = int(time.time())
    payload = {
        # expire in one hour.
        "exp": now + 3600,
        "iat": now,
    }
    if args.iss:
        payload["iss"] = args.iss

    if args.sub:
        payload["sub"] = args.sub
    else:
        payload["sub"] = args.iss

    if args.aud:
        if "," in args.aud:
            payload["aud"] = args.aud.split(",")
        else:

            BuildModelAction buildModelAction = (BuildModelAction) action;
            Object payload = buildModelAction.getModelName();
            return new QueryModelRequirements(action.getStartParameter(), action.isRunTasks(), payloadHashProvider(payload));
        } else if (action instanceof ClientProvidedBuildAction) {
            SerializedPayload payload = ((ClientProvidedBuildAction) action).getAction();

        fout.close

    now = int(time.time())
    payload = {
        # expire in one hour.
        "exp": now + args.expire,
        "iat": now,
    }
    if args.iss:
        payload["iss"] = args.iss
    if args.sub:
        payload["sub"] = args.sub
    else:
        payload["sub"] = args.iss

    if args.aud:
        if "," in args.aud:
            payload["aud"] = args.aud.split(",")
        else: