docs: def unpack_chunk(chunk_data: str) -> bytes:
      """
      Unpacks a previously packed chunk data back into the original
      bytes representation
  
      :param chunk_data:
          The compressed, base64 encoded string to convert back to the
          source bytes object.
      """
  
      if not chunk_data:
          return b''
  
      chunk_compressed = binascii.a2b_base64(chunk_data.encode('utf-8'))
      return zlib.decompress(chunk_compressed)