# File lib/xtemplate/xml.rb, line 322
    def xmldecl(version, encoding, standalone)
      content = []
      if( version )
        content.push("version=\"#{version}\"")
      end
      if( encoding )
        content.push("encoding=\"#{encoding}\"")
      end
      if( standalone )
        content.push("standalone=\"#{standalone}\"")
      end
      push_content("<?xml #{content.join(' ')}?>", NEWLINE)
    end