anchor.diff:    return files;
   }
   
  +/// Loads the file contents of all [files] as bytes.
  +Set<Uint8List> loadFileContentsAsBytes(Set<Source> files) {
  +  return files.map((Source source) {
  +    final bytes = utf8.encode(source.contents.data) as Uint8List;
  +    // CFE needs files to e 0-terminated.
  +    return Uint8List(bytes.length + 1)
  +      ..setRange(0, bytes.length, bytes)
  +      ..[bytes.length] = 0;
  +  }).toSet();
  +}
  +
   /// Sets up analyzer to be able to load and resolve app, packages, and sdk
   /// sources.
   void setup(String path) {
  
positive.code: 
    setup(path.fromUri(entryUri));
  
    Set<Source> files = scanReachableFiles(entryUri);
    var handlers = {
      'scan': () async => scanFiles(files),
      'parse': () async => parseFiles(files),
    };
  
    var handler = handlers[bench];
    if (handler == null) {
  
negative.code: /// outlines).
  library front_end.tool.perf;
  
  import 'dart:convert';
  import 'dart:io' show Directory, File, Platform, exit;
  import 'dart:typed_data';
  
  import 'package:_fe_analyzer_shared/src/scanner/scanner.dart';
  import 'package:analyzer/dart/analysis/features.dart';
  