code: public com.google.protobuf.TimestampOrBuilder getTimestampValueOrBuilder() {
      if (typeCase_ == 5) {
        return (com.google.protobuf.Timestamp) type_;
      }
      return com.google.protobuf.Timestamp.getDefaultInstance();
    }
docs: <code>.google.protobuf.Timestamp timestamp_value = 5;</code>