# File rbot/plugins.rb, line 154
    def cleanup
      @@plugins.values.uniq.each {|p|
        next unless(p.respond_to?("cleanup"))
        begin
          p.cleanup
        rescue StandardError, NameError, SyntaxError => err
          puts "plugin #{p.name} cleanup() failed: " + err
          puts err.backtrace.join("\n")
        end
      }
    end