anchor.diff:  }
   
   Future<void> _startServer(String command, List<String> buildArgs,
  -    {bool? ensureCleanBuild, List<Function>? extraExpects}) async {
  +    {bool? ensureCleanBuild}) async {
     ensureCleanBuild ??= false;
  -  extraExpects ??= [];
   
     // Make sure this is a clean build
     if (ensureCleanBuild && await _toolDir.exists()) {
  
positive.code: /// build to complete.
  ///
  /// To ensure a clean build, set [ensureCleanBuild] to `true`.
  ///
  /// This expects the first build to complete successfully, but you can add extra
  /// expects that happen before that using [extraExpects]. All of these will be
  /// invoked and awaited before awaiting the next successful build.
  Future<void> startServer(
          {bool? ensureCleanBuild,
          List<Function>? extraExpects,
          List<String>? buildArgs}) =>
      _startServer(
          'dart',
          [
            '--packages=.packages',
            p.join('..', 'build_runner', 'bin', 'build_runner.dart'),
            'serve',
            '--verbose',
            if (buildArgs != null) ...buildArgs,
          ],
          ensureCleanBuild: ensureCleanBuild,
          extraExpects: extraExpects);
  
  Future<ProcessResult> _runBuild(String command, List<String> args,
      {bool? ensureCleanBuild}) async {
  
negative.code:   stdOutLines.listen((line) => printOnFailure('StdOut: $line'));
    stdErrLines.listen((line) => printOnFailure('StdErr: $line'));
  
    await nextSuccessfulBuild;
  }
  
  /// Kills the current build script.
  