anchor.diff:      useLocalDirectory = true;
     }
     setUp(copyFilesToTempDirectory);
  +  tearDown(deleteGeneratedFiles);
     test("Test round trip message extraction, translation, code generation, "
         "and printing", () {
       var makeSureWeVerify = expectAsync(runAndVerify);
  
positive.code:       return generateCodeFromTranslation(result);
      }).then(makeSureWeVerify).then(checkResult);
    });
    tearDown(deleteGeneratedFiles);
  }
  
  void copyFilesToTempDirectory() {
  
negative.code: void deleteGeneratedFiles() {
    if (useLocalDirectory) return;
    try {
      new Directory(tempDir).deleteSync(recursive: true);
    } on Error catch (e) {
      print("Failed to delete $tempDir");
      print("Exception:\n$e");
  