private void addDocumentAsAffected(@NotNull DocumentReference documentReference) {
    ClientState state = getClientState();
    if (state == null || state.myCurrentMerger == null || state.myCurrentMerger.hasChangesOf(documentReference, true)) {
      return;
    }

    DocumentReference[] refs = {documentReference};
    state.myCurrentMerger.addAction(new MentionOnlyUndoableAction(refs));
  }
private void addDocumentAsAffected(@NotNull DocumentReference documentReference)