# File lib/multimethod/multimethod.rb, line 133
    def lookup_method_cached_(args)
      args_type = args.collect{|x| x.class}

      # THREAD CRITICAL BEGIN
      unless result = @lookup_method[args_type]
        result = @lookup_method[args_type] =
          lookup_method_(args_type)
      end
      # THREAD CRITICAL END

      result
    end