anchor.diff:    var step = arguments[0];
     var testDir = arguments[1];
   
  +  // If the test directory is just a single identifier, assume it's a language
  +  // test subdirectory.
  +  if (!testDir.contains("/")) testDir = "language_2/$testDir";
  +
     switch (step) {
       case "branch":
         _createBranch(testDir);
  
positive.code:   }
  
    print(green("Copied files from $testDir -> ${toNnbdPath(testDir)}."));
    print("Next, commit the new files and upload a new CL with them:");
    print("");
    print(bold("  git add ."));
    print(bold("  git commit -m \"Migrate $testDir to NNBD\"."));
    print(bold("  git cl upload --bypass-hooks"));
    _showNextStep("Then use analyzer to migrate the files", "analyze", testDir);
  }
  
negative.code: 
      case "copy":
        _copyFiles(testDir);
        break;
  
      case "fork":
        _forkFiles(testDir);
        break;
  
      case "analyze":
  