class Byebug::History

def to_s(n_cmds)
  show_size = n_cmds ? specific_max_size(n_cmds) : default_max_size
  commands = Readline::HISTORY.to_a.last(show_size)
  last_ids(show_size).zip(commands).map do |l|
    format('%5d  %s', l[0], l[1])
  end.join("\n") + "\n"
end