code: def setUp(self):
      super().setUp()
      self.storage = MemoryMediaFileStorage("/mock/endpoint")
      self.media_file_manager = MediaFileManager(self.storage)
      random.seed(1337)
  
imports: import random
  import unittest
  from typing import Optional
  from unittest import TestCase, mock
  from unittest.mock import MagicMock, call, mock_open
  from streamlit.runtime.media_file_manager import MediaFileManager
  from streamlit.runtime.media_file_storage import MediaFileKind
  from streamlit.runtime.memory_media_file_storage import MemoryFile, MemoryMediaFileStorage, _calculate_file_id
  from tests.exception_capturing_thread import call_on_threads
label_desc: Use image node_id 1 for calling the MediaFileManagerThreadingTest obj's underlying member method code with example usage: obj.setUp() without return types