docs: def _execute(self, app_, file_):
          """Run app with file as input.
  
          :param app_: application to run.
          :param file_: file to run app with.
          :return: success True, else False
          :rtype: bool
          """
          app_name = os.path.basename(app_)
          args = [app_]
          args.extend(self.args[app_])
          args.append(file_)
          process = subprocess.Popen(args)
  
          time.sleep(1)
          status = {True: Status.SUCCESS, False: Status.FAILED}
          crashed = process.poll()
          result = status[crashed is None]
          self.stats_.add(app_name, result)
          if result is Status.SUCCESS:
              # process did not crash, so just terminate it
              process.terminate()