@Override
 public FoldRegion createFoldRegion(
     int startOffset,
     int endOffset,
     @NotNull String placeholder,
     @Nullable FoldingGroup group,
     boolean neverExpands) {
   FoldRegionImpl region =
       new FoldRegionImpl(myEditor, startOffset, endOffset, placeholder, group, neverExpands);
   LOG.assertTrue(region.isValid());
   return region;
 }