  static ProtobufWkt::Struct getExpectedPayload(const std::vector<std::string>& issuers) {
    ProtobufWkt::Struct struct_obj;
    auto* fields = struct_obj.mutable_fields();
    for (const auto& issuer : issuers) {
      ProtobufWkt::Struct empty_struct;
      *(*fields)[issuer].mutable_struct_value() = empty_struct;
    }
    return struct_obj;
  }
  static ProtobufWkt::Struct getExpectedPayload(const std::vector<std::string>& issuers) {
    ProtobufWkt::Struct struct_obj;
    auto* fields = struct_obj.mutable_fields();
    for (const auto& issuer : issuers) {
      ProtobufWkt::Struct empty_struct;
      *(*fields)[issuer].mutable_struct_value() = empty_struct;
    }
    return struct_obj;
  }