private void addDuplicate(@NotNull Set<Pair<Boolean, String>> duplicates,
                              boolean isBefore,
                              @Nullable ContentRevision revision) {
      if (revision != null) {
        duplicates.add(Pair.create(isBefore, getRelativePath(revision)));
      }
    }
private void addDuplicate(@NotNull Set<Pair<Boolean, String>> duplicates,
                              boolean isBefore,
                              @Nullable ContentRevision revision)