public void accumulateFiles(final UpdatedFiles from, final DuplicateLevel duplicateLevel) {
    final Parent topLevel = new TopLevelParent();
    for (FileGroup fromGroup : from.getTopLevelGroups()) {
      copyGroup(topLevel, fromGroup, duplicateLevel);
    }
  }
public void accumulateFiles(final UpdatedFiles from, final DuplicateLevel duplicateLevel)