@SuppressWarnings({"rawtypes"})
    @Override
    protected com.google.protobuf.MapField internalGetMapField(
        int number) {
      switch (number) {
        case 18:
          return internalGetCardsmap();
        default:
          throw new RuntimeException(
              "Invalid map field number: " + number);
      }
    }
Protobuf type {@code com.alibaba.fastjson2.dubbo.GooglePBRequestType}
core/src/test/java/com/alibaba/fastjson2/dubbo/GoogleProtobufBasic.java