anchor.diff:  bool _isWebSocketDisconnect(e) {
     return e is NetworkRpcException;
   }
  +
   
   const String _TESTEE_ENV_KEY = 'SERVICE_TEST_TESTEE';
   const Map<String, String> _TESTEE_SPAWN_ENV = const {
  
positive.code:   bool killedByTester = false;
  
    _ServiceTesteeLauncher() :
        args = ['--enable-vm-service:0',
                Platform.script.toFilePath()] {}
  
    String get executablePath => Platform.executable;
  
    // Spawn the testee process.
    Future<Process> _spawnProcess(bool pause_on_start,
  
negative.code:                                 bool trace_compiler) {
      assert(pause_on_start != null);
      assert(pause_on_exit != null);
      assert(pause_on_unhandled_exceptions != null);
      assert(trace_service != null);
      assert(trace_compiler != null);
  
      // TODO(turnidge): I have temporarily turned on service tracing for
      // all tests to help diagnose flaky tests.
      trace_service = true;
  
      if (_shouldLaunchSkyShell()) {
        return _spawnSkyProcess(pause_on_start,
                                pause_on_exit,
                                pause_on_unhandled_exceptions,
                                trace_service,
                                trace_compiler);
      } else {
        return _spawnDartProcess(pause_on_start,
                                 pause_on_exit,
                                 pause_on_unhandled_exceptions,
                                 trace_service,
                                 trace_compiler);
      }
    }
  
    Future<Process> _spawnDartProcess(bool pause_on_start,
                                      bool pause_on_exit,
                                      bool pause_on_unhandled_exceptions,
                                      bool trace_service,
                                      bool trace_compiler) {
      assert(!_shouldLaunchSkyShell());
  
      String dartExecutable = Platform.executable;
  
      var fullArgs = [];
      if (trace_service) {
        fullArgs.add('--trace-service');
  