docstr: Test that storage.clear() removes all storage files from disk.
docstr_tok: ["Test","that","storage.clear","(",")","removes","all","storage","files","from","disk","."]
code: def test_storage_clear(self):
      """Test that storage.clear() removes all storage files from disk."""
      self.storage.set("some-key", b"some-value")
      self.storage.set("another-key", b"another-value")
      self.assertTrue(
          os.path.exists(self.tempdir.path + "/func-key-some-key.memo")
      )
      self.assertTrue(
          os.path.exists(
              self.tempdir.path + "/func-key-another-key.memo"
          )
      )
  
      self.storage.clear()
  
      self.assertFalse(
          os.path.exists(self.tempdir.path + "/func-key-some-key.memo")
      )
      self.assertFalse(
          os.path.exists(
              self.tempdir.path + "/func-key-another-key.memo"
          )
      )
  
      with self.assertRaises(CacheStorageKeyNotFoundError):
          self.storage.get("some-key")
  
      with self.assertRaises(CacheStorageKeyNotFoundError):
          self.storage.get("another-key")
  
      # test that cache folder is empty
      self.assertEqual(os.listdir(self.tempdir.path), [])
  
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 9 for calling the LocalDiskPersistCacheStorageTest obj's underlying member method code with example usage: obj.test_storage_clear() without return types