private com.google.protobuf.SingleFieldBuilder<
          org.bwapi.proxy.messages.GameMessages.UnitId, org.bwapi.proxy.messages.GameMessages.UnitId.Builder, org.bwapi.proxy.messages.GameMessages.UnitIdOrBuilder> 
          getAddonFieldBuilder() {
        if (addonBuilder_ == null) {
          addonBuilder_ = new com.google.protobuf.SingleFieldBuilder<
              org.bwapi.proxy.messages.GameMessages.UnitId, org.bwapi.proxy.messages.GameMessages.UnitId.Builder, org.bwapi.proxy.messages.GameMessages.UnitIdOrBuilder>(
                  addon_,
                  getParentForChildren(),
                  isClean());
          addon_ = null;
        }
        return addonBuilder_;
      }