def fetch_comments_async(prs)
      threads = []

      prs.each_slice(MAX_THREAD_NUMBER) do |prs_slice|
        prs_slice.each do |pr|
          threads << Thread.new do
            pr["comments"] = []
            iterate_pages(@client, "issue_comments", pr["number"]) do |new_comment|
              pr["comments"].concat(new_comment)
            end
            pr["comments"] = pr["comments"].map { |comment| stringify_keys_deep(comment.to_hash) }
          end
        end
        threads.each(&:join)
        threads = []
      end
      nil
    end
def fetch_comments_async(prs)
      threads = []

      prs.each_slice(MAX_THREAD_NUMBER) do |prs_slice|
        prs_slice.each do |pr|
          threads << Thread.new do
            pr["comments"] = []
            iterate_pages(@client, "issue_comments", pr["number"]) do |new_comment|
              pr["comments"].concat(new_comment)
            end
            pr["comments"] = pr["comments"].map { |comment| stringify_keys_deep(comment.to_hash) }
          end
        end
        threads.each(&:join)
        threads = []
      end
      nil
    end
Fetch comments for PRs and add them to "comments"

 @param [Array] prs The array of PRs.
 @return [Void] No return; PRs are updated in-place.