anchor.diff:    _ListenerDirective(Logger this.logger);
     call(String text) => logger(text);
   }
  +
  +@NgFilter(name:'hello')
  +class _HelloFilter {
  +  call(String str) {
  +    return 'Hello, $str!';
  +  }
  +}
  +
  
positive.code:     TestBed _;
      beforeEach(module((Module module) {
        module.type(_ListenerDirective);
      }));
      beforeEach(inject((TestBed tb) => _ = tb));
  
  
negative.code:       $rootScope.$digest();
        expect(element.attr('multiline-attr')).toEqual('line1: L1\nline2: L2');
      }));
  
  
      it('should handle filters', inject((Compiler $compile, Scope $rootScope, Injector injector, DirectiveMap directives) {
        var element = $('<div>{{"World" | hello}}</div>');
        var template = $compile(element, directives);
        var block = template(injector);
        $rootScope.$digest();
  
        element = $(block.elements);
  
        expect(element.html()).toEqual('Hello, World!');
      }));
    });
  
    describe('NgShow', () {
  