code: def get_stored_content_length(headers):
    
    length = headers.get('x-goog-stored-content-length')
    if length is None:
      length = headers.get('content-length')
    return length
docs: Return the content length (in bytes) of the object as stored in GCS.
  
    x-goog-stored-content-length should always be present except when called via
    the local dev_appserver. Therefore if it is not present we default to the
    standard content-length header.
  
    Args:
      headers: a dict of headers from the http response.
  
    Returns:
      the stored content length.