docstr: MediaFileManager.add raises a TypeError if it's passed None.
docstr_tok: ["MediaFileManager.add","raises","a","TypeError","if","it","'s","passed","None","."]
code: def test_reject_null_files(self):
      """MediaFileManager.add raises a TypeError if it's passed None."""
      with self.assertRaises(TypeError):
          self.media_file_manager.add(
              None, "media/any", random_coordinates()
          )
  
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 4 for calling the MediaFileManagerTest obj's underlying member method code with example usage: obj.test_reject_null_files() without return types