@Override
  protected boolean preprocessUsages(@NotNull final Ref<UsageInfo[]> refUsages) {
    final MultiMap<PsiElement, @DialogMessage String> conflicts = new MultiMap<>();
    if (!ProgressManager.getInstance()
      .runProcessWithProgressSynchronously(() -> ReadAction.run(() -> collectConflicts(conflicts)), 
                                           RefactoringBundle.message("detecting.possible.conflicts"), true, myProject)) {
      return false;
    }

    checkConflicts(refUsages, conflicts);
    return showConflicts(conflicts, refUsages.get());
  }
@Override
  protected boolean preprocessUsages(@NotNull final Ref<UsageInfo[]> refUsages)