code: def test_setting_filename_suffix_works(self):
      logdir = s3_temp_dir()
  
      w = EventFileWriter(logdir, filename_suffix=".event_horizon")
      w.close()
      event_files = sorted(gfile.glob(s3_join(logdir, "*")))
      self.assertEqual(event_files[0].split(".")[-1], "event_horizon")
  
file_path: tensorboard/tensorboard/summary/writer/event_file_writer_s3_test.py
imports: import boto3
  import os
  import unittest
  from tensorboard.summary.writer.event_file_writer import EventFileWriter
  from tensorboard.compat import tf
  from tensorboard.compat.proto import event_pb2
  from tensorboard.compat.proto.summary_pb2 import Summary
  from tensorboard.compat.tensorflow_stub.io import gfile
  from tensorboard.compat.tensorflow_stub.pywrap_tensorflow import PyRecordReader_New
  from moto import mock_s3
  from tensorboard import test
label_desc: Use image node_id 2 for calling the EventFileWriterTest obj's underlying member method code with example usage: obj.test_setting_filename_suffix_works() without return types