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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _write_json_blob(encoded_value, pipeline_id=None):
 """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. """


  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)