code: def testMultipleFilesAtOnce(self):
      self._WriteToFile("b", "b")
      self._WriteToFile("a", "a")
      self.assertWatcherYields(["a", "b"])
      self.assertFalse(self._watcher.OutOfOrderWritesDetected())
  
imports: import os
  import shutil
  import tensorflow
  from tensorboard.backend.event_processing import directory_watcher
  from tensorboard.backend.event_processing import io_wrapper
label_desc: Use image node_id 11 for calling the DirectoryWatcherTest obj's underlying member method code with example usage: obj.testMultipleFilesAtOnce() without return types