# File lib/rbot/ircbot.rb, line 1231
  def help(topic=nil)
    topic = nil if topic == ""
    case topic
    when nil
      helpstr = _("help topics: ")
      helpstr += @plugins.helptopics
      helpstr += _(" (help <topic> for more info)")
    else
      unless(helpstr = @plugins.help(topic))
        helpstr = _("no help for topic %{topic}") % { :topic => topic }
      end
    end
    return helpstr
  end