anchor.diff:      'a|baz.scss.css': r'',
     });
   
  -  testPhases('supports descending and attribute selectors', phases, {
  +  testPhasesAsync('supports descending and attribute selectors', phases, {
       'a|foo.css': r'''
         html body input[type="submit"] {}
         html body input[type="checkbox"] {}
  
positive.code:       present-element {}
      '''
    });
    testPhases('prunes css based on angular2 annotations in .dart companion', phases, {
      'a|foo.css': r'''
        absent-element {}
        present-element {}
  
negative.code:     ''',
    });
  
    testPhasesAsync('processes class attributes with mustaches', phases, {
      'a|foo.css': r'''
        .what_1 {}
        .what-2 {}
  