anchor.diff:        bytes.replaceRange(
             fix.offset, fix.offset + fix.length, UTF8.encode(fix.replacement));
       }
  -    await new File.fromUri(uri).writeAsBytes(bytes);
  +    await file.writeAsBytes(bytes);
     }
   
     /// Loads expectations from the source file located at [uri].
  
positive.code:   /// form suitable for printing to the console.
    ///
    /// Should be called after [finish].
    get problemsAsString => _problems.join('\n');
  
    /// Checks whether the property/value pairs passed to [record] match the
    /// expectations loaded by [loadExpectations].
  
negative.code:   Future<Null> fixSource(Uri uri) async {
      var fixes = _fixes[uri];
      if (fixes == null) return;
      File file = new File.fromUri(uri);
      var bytes = await file.readAsBytes();
      // Apply the fixes in reverse order so that offsets don't need to be
      // adjusted after each fix.
      fixes.sort((a, b) => b.offset.compareTo(a.offset));
  