void SerializeNumberProperty(const std::string &key, size_t number, json &obj) {
  JsonAddMember(obj, key.c_str(), json(static_cast<uint64_t>(number)));
}
void SerializeNumberProperty(const std::string &key, size_t number, json &obj) {
  JsonAddMember(obj, key.c_str(), json(static_cast<uint64_t>(number)));
}