@Override
  public ProgressIndicator findMoreItems(@NotNull Map<? extends SearchEverywhereContributor<?>, Collection<SearchEverywhereFoundElementInfo>> alreadyFound,
                                         @NotNull Map<? extends SearchEverywhereContributor<?>, Integer> contributorsAndLimits,
                                         @NotNull String pattern) {
    if (contributorsAndLimits.size() > 1)
      throw new IllegalArgumentException("Multiple contributors are not allowed for grouped list");

    Map.Entry<? extends SearchEverywhereContributor<?>, Integer> entry = contributorsAndLimits.entrySet().stream().findFirst()
      .orElseThrow(() -> new IllegalArgumentException("Empty contributors map is not allowed"));
    SearchEverywhereContributor<?> contributor = entry.getKey();
    int newLimit = entry.getValue();

    ProgressIndicator indicator = new ProgressIndicatorBase();
    ResultsAccumulator accumulator = new ShowMoreResultsAccumulator(alreadyFound, myEqualityProvider, contributor, newLimit,
                                                                    myListener, myNotificationExecutor, indicator);
    indicator.start();
    accumulator.startSearch(pattern);
    Runnable task = createSearchTask(pattern, accumulator, indicator, contributor, () -> indicator.stop());
    ApplicationManager.getApplication().executeOnPooledThread(task);

    return indicator;
  }
@Override
  public ProgressIndicator findMoreItems(@NotNull Map<? extends SearchEverywhereContributor<?>, Collection<SearchEverywhereFoundElementInfo>> alreadyFound,
                                         @NotNull Map<? extends SearchEverywhereContributor<?>, Integer> contributorsAndLimits,
                                         @NotNull String pattern)