anchor.diff:      group('in-dir', () {
         test('file-exists', () {
           expect(HttpServer.bind('localhost', 0).then((server) {
  -          var dir = new Directory('').createTempSync();
  +          var dir = Directory.systemTemp.createTempSync('http_server_virtual_');
             var dir2 = new Directory('${dir.path}/dir')..createSync();
             var file = new File('${dir2.path}/file')..createSync();
             var virDir = new VirtualDirectory(dir.path);
  
positive.code:     testEncoding(name, expected, [bool create = true]) {
        test('encode-$name', () {
          expect(HttpServer.bind('localhost', 0).then((server) {
          var dir = new Directory('').createTempSync();
            if (create) new File('${dir.path}/$name').createSync();
            var virDir = new VirtualDirectory(dir.path);
            virDir.allowDirectoryListing = true;
  
negative.code: 
      test('encoded-path-separator', () {
        expect(HttpServer.bind('localhost', 0).then((server) {
          var dir = Directory.systemTemp.createTempSync('http_server_virtual_');
          new Directory('${dir.path}/a').createSync();
          new Directory('${dir.path}/a/b').createSync();
          new Directory('${dir.path}/a/b/c').createSync();
  