"ETag",
            "v1",
            "Vary",
            "Accept-Charset",
            "Donut",
            "a",
          ),
        body = "A",
      ),
    )
    server.enqueue(
      MockResponse.Builder()
        .clearHeaders()
        .addHeader("Donut: b")
        .code(HttpURLConnection.HTTP_NOT_MODIFIED)
        .build(),
    )
    client =