code: def testEmptyDirectory(self):
      self.assertWatcherYields([])
  
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 7 for calling the DirectoryWatcherTest obj's underlying member method code with example usage: obj.testEmptyDirectory() without return types