code: private void assignUniqueLabel(Package pack, Package targetPackage) {
      Set<String> existingLabels;
      if (targetPackage != null) {
        existingLabels = stream(targetPackage.getChildren()).map(Package::getLabel).collect(toSet());
      } else {
        existingLabels =
            dataService
                .query(PACKAGE, Package.class)
                .eq(PackageMetadata.PARENT, null)
                .findAll()
                .map(Package::getLabel)
                .collect(toSet());
      }
      pack.setLabel(generateUniqueLabel(pack.getLabel(), existingLabels));
    }
docs: Checks if there's a Package in the target location with the same label. If so, keeps adding a
  postfix until the label is unique.