@Override
    public boolean equals(@Nullable FoldRegion o1, @Nullable FoldRegion o2) {
      return o1 == o2 || (o1 != null && o2 != null && o1.getStartOffset() == o2.getStartOffset() && o1.getEndOffset() == o2.getEndOffset());
    }
@Override
    public boolean equals(@Nullable FoldRegion o1, @Nullable FoldRegion o2)