code: protected function getPublishedFormat(array $config)
      {
          if (isset($config['publishedFormat'])) {
              if (!is_string($config['publishedFormat'])) {
                  throw new \DomainException(
                      'publishedFormat must reference a string',
                      self::ERR_INVALID_PUBLISHEDFORMAT
                  );
              }
              return $config['publishedFormat'];
          }
          return 'n/j/y g:i A';
      }
docs: Extracts a pattern for formatting video publish times from
  configuration.
  
  @param array $config
  @return string
  @throws \DomainException if publishedFormat setting is invalid