code: def _write_json_blob(encoded_value, pipeline_id=None):
    
  
    default_bucket = app_identity.get_default_gcs_bucket_name()
    if default_bucket is None:
      raise Exception(
        "No default cloud storage bucket has been set for this application. "
        "This app was likely created before v1.9.0, please see: "
        "https://cloud.google.com/appengine/docs/php/googlestorage/setup")
  
    path_components = ['/', default_bucket, "appengine_pipeline"]
    if pipeline_id:
      path_components.append(pipeline_id)
    path_components.append(uuid.uuid4().hex)
    # Use posixpath to get a / even if we're running on windows somehow
    file_name = posixpath.join(*path_components)
    with cloudstorage.open(file_name, 'w', content_type='application/json') as f:
      for start_index in xrange(0, len(encoded_value), _MAX_JSON_SIZE):
        end_index = start_index + _MAX_JSON_SIZE
        f.write(encoded_value[start_index:end_index])
  
    key_str = blobstore.create_gs_key("/gs" + file_name)
    logging.debug("Created blob for filename = %s gs_key = %s", file_name, key_str)
    return blobstore.BlobKey(key_str)
docs: Writes a JSON encoded value to a Cloud Storage File.
  
    This function will store the blob in a GCS file in the default bucket under
    the appengine_pipeline directory. Optionally using another directory level
    specified by pipeline_id
    Args:
      encoded_value: The encoded JSON string.
      pipeline_id: A pipeline id to segment files in Cloud Storage, if none,
        the file will be created under appengine_pipeline
  
    Returns:
      The blobstore.BlobKey for the file that was created.