You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: reply_keyboard_markup.rb
    path of file: ./repos/telegram-bot-ruby/lib/telegram/bot/types
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Telegram
  module Bot
    module Types
      class 
    
        def to_compact_hash
          hsh = super
          hsh[:keyboard].map! do |arr|
            arr.map do |item|
              item.is_a?(KeyboardButton) ? item.to_compact_hash : item
            end
          end

          hsh
        end