    # File lib/gettext.rb, line 71
      def bindtextdomain_to(klass, domainname, *options)
        if options[0].kind_of? Hash
          opts = options[0]
        else
          # for backward compatibility.
          opts = {}
          opts[:path] = options[0] if options[0]
          opts[:output_charset] = options[2] if options[2]
        end
        unless (klass.kind_of? GetText or klass.include? GetText)
          klass.__send__(:include, GetText)
        end
        TextDomainManager.bind_to(klass, domainname, opts)
      end