docstr: Test that storage.set() overrides the value of an existing key.
docstr_tok: ["Test","that","storage.set","(",")","overrides","the","value","of","an","existing","key","."]
code: def test_storage_set_override(self):
      """Test that storage.set() overrides the value of an existing key."""
      self.storage.set("another_key", b"another_value")
      self.storage.set("another_key", b"new_value")
      self.assertEqual(self.storage.get("another_key"), b"new_value")
  
imports: import logging
  import math
  import os.path
  import shutil
  import unittest
  from unittest.mock import MagicMock, patch
  from testfixtures import TempDirectory
  from streamlit import util
  from streamlit.logger import get_logger
  from streamlit.runtime.caching.storage import CacheStorageContext, CacheStorageError, CacheStorageKeyNotFoundError
  from streamlit.runtime.caching.storage.in_memory_cache_storage_wrapper import InMemoryCacheStorageWrapper
  from streamlit.runtime.caching.storage.local_disk_cache_storage import LocalDiskCacheStorage, LocalDiskCacheStorageManager
label_desc: Use image node_id 7 for calling the LocalDiskPersistCacheStorageTest obj's underlying member method code with example usage: obj.test_storage_set_override() without return types