anchor.diff:    }
   
     factory PipelineCommand.runWithPreviousKernelOutput(
  -      CompilerConfiguration conf) {
  -    return new PipelineCommand._(conf,
  +      CompilerConfiguration configuration) {
  +    return new PipelineCommand._(configuration,
           (List<String> globalArguments, String previousOutput) {
         assert(previousOutput.endsWith('.dill'));
  -      return replaceDartFileWith(globalArguments, previousOutput);
  +      return _replaceDartFiles(globalArguments, previousOutput);
       });
     }
   
  
positive.code: 
    PipelineCommand._(this.compilerConfiguration, this._argumentsFunction);
  
    factory PipelineCommand.runWithGlobalArguments(CompilerConfiguration conf) {
      return new PipelineCommand._(conf,
          (List<String> globalArguments, String previousOutput) {
        assert(previousOutput == null);
        return globalArguments;
      });
    }
  
    factory PipelineCommand.runWithDartOrKernelFile(CompilerConfiguration conf) {
      return new PipelineCommand._(conf,
          (List<String> globalArguments, String previousOutput) {
        var filtered = globalArguments
            .where(
                (String name) => name.endsWith('.dart') || name.endsWith('.dill'))
            .toList();
        assert(filtered.length == 1);
        return filtered;
  
negative.code:       List<String> sharedOptions,
        List<String> originalArguments,
        CommandArtifact artifact) {
      Uri sdk = _useSdk
          ? new Uri.directory(buildDir).resolve('dart-sdk/')
          : new Uri.directory(TestUtils.dartDir.toNativePath()).resolve('sdk/');
      Uri preambleDir = sdk.resolve('lib/_internal/js_runtime/lib/preambles/');
      return runtimeConfiguration.dart2jsPreambles(preambleDir)
        ..add(artifact.filename);
  