in src/workers/producer/send_message.h [58:69]
void HandleOKCallback()
{
Nan::HandleScope scope;
Local<Value> argv[] = {
Nan::Undefined(),
Nan::New<v8::Number>((unsigned int)send_ret.sendStatus),
Nan::New<v8::String>(send_ret.msgId).ToLocalChecked(),
Nan::New<v8::Number>((long long)send_ret.offset)
};
callback->Call(4, argv);
}