docstr: Get a URL for a given media file. Raise a MediaFileStorageError if
  no such file exists.
docstr_tok: ["Get","a","URL","for","a","given","media","file",".","Raise","a","MediaFileStorageError","if","no","such","file","exists","."]
code: def get_url(self, file_id: str) -> str:
      """Get a URL for a given media file. Raise a MediaFileStorageError if
      no such file exists.
      """
      media_file = self.get_file(file_id)
      extension = get_extension_for_mimetype(media_file.mimetype)
      return f"{self._media_endpoint}/{file_id}{extension}"
  
imports: import contextlib
  import hashlib
  import mimetypes
  import os.path
  from typing import Dict, List, NamedTuple, Optional, Union
  from typing_extensions import Final
  from streamlit.logger import get_logger
  from streamlit.runtime.media_file_storage import MediaFileKind, MediaFileStorage, MediaFileStorageError
  from streamlit.runtime.stats import CacheStat, CacheStatsProvider, group_stats
  from streamlit.util import HASHLIB_KWARGS
label_desc: Use image node_id 4 for calling the MemoryMediaFileStorage obj's underlying member method code with example usage: obj.get_url(file_id) and returns: self, str, file_id, extension