anchor.diff:    _normalizerExp1 ??= new RegExp(r'\s+');
     _normalizerExp2 ??= new RegExp(r':\s');
     _normalizerExp3 ??= new RegExp('' + "'" + r'');
  -  _normalizerExp4 ??= new RegExp('{ ');
  -  _normalizerExp5 ??= new RegExp(' }');
  +  _normalizerExp4 ??= new RegExp(r'\s*{');
  +  _normalizerExp5 ??= new RegExp(r'}(?!}|$)');
     _normalizerExp6 ??= new RegExp(r'url\((\"|\s)(.+)(\"|\s)\)(\s*)');
     _normalizerExp7 ??= new RegExp(r'\[(.+)=([^"\]]+)\]');
     css = css.replaceAll(_normalizerExp1, ' ');
     css = css.replaceAll(_normalizerExp2, ':');
     css = css.replaceAll(_normalizerExp3, '"');
  -  css = css.replaceAll(_normalizerExp4, '{');
  -  css = css.replaceAll(_normalizerExp5, '}');
  +  css = css.replaceAll(_normalizerExp4, ' {');
  +  css = css.replaceAll(_normalizerExp5, '} ');
     css = css.replaceAllMapped(_normalizerExp6, (match) => 'url("${match[2]}")');
     css = css.replaceAllMapped(
         _normalizerExp7, (match) => '[${match[1]}="${match[2]}"]');
  
positive.code:   test('should handle media rules', () {
      var css = '@media screen and (max-width:800px) {div {font-size:50px;}}';
      var expected =
          '@media screen AND (max-width:800px){div.$content {font-size:50px;}}';
      shimAndExpect(css, expected);
    });
  
  
negative.code: 
    test('should shim rules after @import', () {
      var css = '@import url("a"); div {}';
      shimAndExpect(css, '@import url("a");div.$content {}');
    });
  
    test('should leave calc() unchanged', () {
  