return client.newCall(request).execute()
  }

  /**
   * @param delta the offset from the current date to use. Negative values yield dates in the past;
   *     positive values yield dates in the future.
   */
  private fun formatDate(
    delta: Long,
    timeUnit: TimeUnit,
  ): String? {
    return formatDate(Date(System.currentTimeMillis() + timeUnit.toMillis(delta)))
  }