@ApiStatus.Internal
  public @Nullable RangeMarker findFocusRegion(int start, int end) {
    RangeMarker[] found = new RangeMarker[1];
    myFocusMarkerTree.processOverlappingWith(start, end, range -> {
      if (range.getStartOffset() == start && range.getEndOffset() == end) {
        found[0] = range;
        return false;
      }
      return true;
    });
    return found[0];
  }
@ApiStatus.Internal
  public @Nullable RangeMarker findFocusRegion(int start, int end)