# File lib/rbot/botuser.rb, line 762
      def login(user, botusername, pwd=nil)
        ircuser = user.to_irc_user
        n = BotUser.sanitize_username(botusername)
        k = n.to_sym
        raise "No such BotUser #{n}" unless include?(k)
        if @botusers.has_key?(ircuser)
          return true if @botusers[ircuser].username == n
          # TODO
          # @botusers[ircuser].logout(ircuser)
        end
        bu = @allbotusers[k]
        if bu.login(ircuser, pwd)
          @botusers[ircuser] = bu
          return true
        end
        return false
      end