private void beforeFileDeletion(@NotNull VFileDeleteEvent e) {
    VirtualFile file = e.getFile();
    if (!shouldProcess(e, file)) {
      invalidateActionsFor(file);
      return;
    }
    if (isUndoable(e, file)) {
      file.putUserData(DELETION_WAS_UNDOABLE, createDocumentReference(file));
    }
    else {
      registerNonUndoableAction(file);
    }
  }
private void beforeFileDeletion(@NotNull VFileDeleteEvent e)