@SuppressWarnings({"rawtypes"})
      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