private @Nullable TextAttributes getInnerHighlighterAttributes(@NotNull FoldRegion region) {
      if (region.areInnerHighlightersMuted()) return null;
      List<RangeHighlighterEx> innerHighlighters = new ArrayList<>();
      collectVisibleInnerHighlighters(region, myEditorMarkup, innerHighlighters);
      collectVisibleInnerHighlighters(region, myDocMarkup, innerHighlighters);
      if (innerHighlighters.isEmpty()) return null;
      innerHighlighters.sort(IterationState.createByLayerThenByAttributesComparator(myEditor.getColorsScheme()));
      Color fgColor = null;
      Color bgColor = null;
      Color effectColor = null;
      EffectType effectType = null;
      for (RangeHighlighter h : innerHighlighters) {
        TextAttributes attrs = h.getTextAttributes(myEditor.getColorsScheme());
        if (attrs == null) continue;
        if (fgColor == null && attrs.getForegroundColor() != null) fgColor = attrs.getForegroundColor();
        if (bgColor == null && attrs.getBackgroundColor() != null) bgColor = attrs.getBackgroundColor();
        if (effectColor == null && attrs.getEffectColor() != null) {
          EffectType type = attrs.getEffectType();
          if (type != null &&
              type != EffectType.BOXED &&
              type != EffectType.ROUNDED_BOX &&
              type != EffectType.SLIGHTLY_WIDER_BOX &&
              type != EffectType.STRIKEOUT) {
            effectColor = attrs.getEffectColor();
            effectType = type;
          }
        }
      }
      return new TextAttributes(fgColor, bgColor, effectColor, effectType, Font.PLAIN);
    }
private @Nullable TextAttributes getInnerHighlighterAttributes(@NotNull FoldRegion region)