.Builder()
          .add("ETag", "v1")
          .add("Cache-Control", "max-age=60")
          .add("Vary", "Accept-Charset")
          .add("Content-Length", "1")
          .build(),
      ).assertRequestUrl(url)
      .assertRequestHeader("Accept-Language", "en-US")
      .assertRequestHeader("Accept-Charset", "UTF-8")
      .assertSentRequestAtMillis(request1SentAt, request1ReceivedAt)