public async Task <IActionResult> Post([FromBody] CommentDto commentDto, CancellationToken ct)
        {
            var comment = _mapper.Map <Comment>(commentDto);

            _context.Comments.Add(comment);

            await _context.SaveChangesAsync(ct).ConfigureAwait(false);

            await _context.IncrementReplyCountAsync(commentDto.ReplyToId.GetValueOrDefault(), ct);

            return(CreatedAtAction("GetComment", new { id = comment.Id }, _mapper.Map <CommentDto>(comment)));
        }