anchor.diff:  library test_progress;
   
   import "dart:io";
  +import "dart:io" as io;
   import "http_server.dart" as http_server;
   import "status_file_parser.dart";
   import "test_runner.dart";
  
positive.code:     _printTimingInformation();
      stdout.close();
      stderr.close();
      if (_failedTests > 0) exit(1);
    }
  
    void _printStartProgress(TestCase test) {}
  
negative.code:     }
      stdout.close();
      stderr.close();
      if (_failedTests > 0) {
        io.exitCode = 1;
      }
    }
  
    void allTestsKnown() {
  