code: def _append_record(self, data):
      with open(self._get_filename(), "ab") as f:
          record_writer.RecordWriter(f).write(data)
  
imports: import abc
  import io
  import os
  import unittest
  from unittest import mock
  from tensorboard import test
  from tensorboard.backend.event_processing import event_file_loader
  from tensorboard.compat import tf
  from tensorboard.compat.proto import event_pb2
  from tensorboard.summary.writer import record_writer
label_desc: Use image node_id 2 for calling the EventFileLoaderTestBase obj's underlying member method code with example usage: obj._append_record(data) without return types