code: def _get_project_id(self):
          
          fpath = os.environ.get('GOOGLE_APPLICATION_CREDENTIALS', None)
          if fpath is None:
              raise Exception('ERROR: No project ID specified, and '
                              'GOOGLE_APPLICATION_CREDENTIALS env var is not set')
          fpath = os.path.abspath(os.path.expanduser(fpath))
          logger.debug('Reading credentials file at %s to get project_id', fpath)
          with open(fpath, 'r') as fh:
              cred_data = json.loads(fh.read())
          return cred_data['project_id']
docs: Get our projectId from the ``GOOGLE_APPLICATION_CREDENTIALS`` creds
          JSON file.
  
          :return: project ID
          :rtype: str