# File htree/output.rb, line 151
    def output_prolog_xmldecl(out, context)
      out.output_string "<?xml version=\"#{@version}\""
      if @encoding
        out.output_string " encoding=\"#{@encoding}\""
      end
      if @standalone != nil
        out.output_string " standalone=\"#{@standalone ? 'yes' : 'no'}\""
      end
      out.output_string "?>"
    end