public Builder mergeAddon(org.bwapi.proxy.messages.GameMessages.UnitId value) {
        if (addonBuilder_ == null) {
          if (((bitField1_ & 0x00200000) == 0x00200000) &&
              addon_ != org.bwapi.proxy.messages.GameMessages.UnitId.getDefaultInstance()) {
            addon_ =
              org.bwapi.proxy.messages.GameMessages.UnitId.newBuilder(addon_).mergeFrom(value).buildPartial();
          } else {
            addon_ = value;
          }
          onChanged();
        } else {
          addonBuilder_.mergeFrom(value);
        }
        bitField1_ |= 0x00200000;
        return this;
      }