"ETag",
            "v1",
            "Cache-Control",
            "max-age=60",
            "Vary",
            "Accept-Charset",
          ),
        body = "A",
      ),
    )
    client =
      client.newBuilder()
        .cache(cache)
        .build()

    // Store a response in the cache.
    val url = server.url("/")