maxSize = maxSize,
      taskRunner = taskRunner,
    )

  // read and write statistics, all guarded by 'this'.
  internal var writeSuccessCount = 0
  internal var writeAbortCount = 0
  private var networkCount = 0
  private var hitCount = 0
  private var requestCount = 0

  val isClosed: Boolean
    get() = cache.isClosed()

  internal fun get(request: Request): Response? {

  @Test
  fun varyMultipleFieldsWithMatch() {
    server.enqueue(
      MockResponse
        .Builder()
        .addHeader("Cache-Control: max-age=60")
        .addHeader("Vary: Accept-Language, Accept-Charset")
        .addHeader("Vary: Accept-Encoding")
        .body("A")
        .build(),
    )
    server.enqueue(
      MockResponse
        .Builder()
        .body("B")
        .build(),

  public static final String KEEP_ALIVE = "Keep-Alive";

  /**
   * The HTTP <a href="https://github.com/WICG/nav-speculation/blob/main/no-vary-search.md">{@code
   * No-Vary-Seearch}</a> header field name.
   *
   * @since 32.0.0
   */
  public static final String NO_VARY_SEARCH = "No-Vary-Search";

  /**
   * The HTTP <a href="https://googlechrome.github.io/OriginTrials/#header">{@code Origin-Trial}</a>
   * header field name.

          println("Server: ${response.header("Server")}")
          println("Date: ${response.header("Date")}")
          println("Vary: ${response.headers("Vary")}")
        }
      }
    ```

=== ":material-language-java: Java"
    ```java
      private final OkHttpClient client = new OkHttpClient();

      public void run() throws Exception {

        logger.info("Stats version: {}", version);
        logger.info("Stats status: {}", status);

        // Verify stats contain expected fields
        // Note: The actual fields may vary depending on the implementation
        // Common fields might include: document count, index size, etc.
        assertTrue(res.size() > 0, "Response should contain stats data");

        logger.info("[END] testRead");

## Documenting the callback { #documenting-the-callback }

The actual callback code will depend heavily on your own API app.

And it will probably vary a lot from one app to the next.

It could be just one or two lines of code, like:

```Python
callback_url = "https://example.com/api/v1/invoices/events/"

    cacheHit
      .cacheResponse()
      .assertCode(200)
      .assertHeader("Donut", "a")
      .assertHeader("ETag", "v1")
      .assertRequestUrl(server.url("/"))
      .assertRequestHeader("Accept-Language") // No Vary on Accept-Language.
      .assertRequestHeader("Accept-Charset", "UTF-8") // Because of Vary on Accept-Charset.

Replace existing GSS/CSE code:

```javascript
<!-- Old GSS/CSE Code -->
<script>
  (function() {
    var cx = 'YOUR-CSE-ID';
    var gcse = document.createElement('script');
    gcse.type = 'text/javascript';
    gcse.async = true;
    gcse.src = 'https://cse.google.com/cse.js?cx=' + cx;
    var s = document.getElementsByTagName('script')[0];
    s.parentNode.insertBefore(gcse, s);
  })();
</script>

       */
      private var smallestHeaderTableSizeSetting = Integer.MAX_VALUE
      private var emitDynamicTableSizeUpdate: Boolean = false

      @JvmField var maxDynamicTableByteCount: Int = headerTableSizeSetting

      // Visible for testing.
      @JvmField var dynamicTable = arrayOfNulls<Header>(8)

    private const val UNICODE_4 = 0x1d11e

    /**
     * Returns a new instance configured with a default encode set for the ASCII range. The specific
     * rules vary per-component: for example, '?' may be identity-encoded in a fragment, but must be
     * percent-encoded in a path.
     *
     * See https://url.spec.whatwg.org/#percent-encoded-bytes
     */