@Override
      public final Builder mergeUnknownFields(
          final com.google.protobuf.UnknownFieldSet unknownFields) {
        return super.mergeUnknownFields(unknownFields);
      }
<code>int32 years = 3;</code>
@return This builder for chaining.
core/src/test/java/com/alibaba/fastjson2/dubbo/GoogleProtobufBasic.java