private com.google.protobuf.RepeatedFieldBuilder<
          org.bwapi.proxy.messages.GameMessages.UpgradeType, org.bwapi.proxy.messages.GameMessages.UpgradeType.Builder, org.bwapi.proxy.messages.GameMessages.UpgradeTypeOrBuilder> 
          getUpgradingFieldBuilder() {
        if (upgradingBuilder_ == null) {
          upgradingBuilder_ = new com.google.protobuf.RepeatedFieldBuilder<
              org.bwapi.proxy.messages.GameMessages.UpgradeType, org.bwapi.proxy.messages.GameMessages.UpgradeType.Builder, org.bwapi.proxy.messages.GameMessages.UpgradeTypeOrBuilder>(
                  upgrading_,
                  ((bitField0_ & 0x00400000) == 0x00400000),
                  getParentForChildren(),
                  isClean());
          upgrading_ = null;
        }
        return upgradingBuilder_;
      }