code: def _WriteToFile(self, filename, data):
      path = os.path.join(self._directory, filename)
      with open(path, "a") as f:
          f.write(data)
  
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 3 for calling the DirectoryWatcherTest obj's underlying member method code with example usage: obj._WriteToFile(filename, data) without return types