public boolean hasDuplicates(Set<? extends VirtualFile> files) {
    initDuplicates(null);
    final DuplicatesFinder finder = getExactDuplicatesFinder();

    final Boolean hasDuplicates = hasDuplicates();
    if (hasDuplicates == null || hasDuplicates) return true;
    if (finder != null) {
      final PsiManager psiManager = PsiManager.getInstance(myProject);
      for (VirtualFile file : files) {
        if (!finder.findDuplicates(psiManager.findFile(file)).isEmpty()) return true;
      }
    }
    return false;
  }
public boolean hasDuplicates(Set<? extends VirtualFile> files)