code: def _load_file_from_gcs(gcs_file_path, credentials=None):
    
    gcs_service = _get_storage_service(credentials)
  
    bucket_name, object_name = gcs_file_path[len('gs://'):].split('/', 1)
    request = gcs_service.objects().get_media(
        bucket=bucket_name, object=object_name)
  
    file_handle = io.BytesIO()
    downloader = MediaIoBaseDownload(file_handle, request, chunksize=1024 * 1024)
    done = False
    while not done:
      _, done = _downloader_next_chunk(downloader)
    filevalue = file_handle.getvalue()
    if not isinstance(filevalue, six.string_types):
      filevalue = filevalue.decode()
    return six.StringIO(filevalue)
docs: Load context from a text file in gcs.
  
    Args:
      gcs_file_path: The target file path; should have the 'gs://' prefix.
      credentials: Optional credential to be used to load the file from gcs.
  
    Returns:
      The content of the text file as a string.