apply {
        this.headers = headers.newBuilder()
      }

    /**
     * Sets this request's `Cache-Control` header, replacing any cache control headers already
     * present. If [cacheControl] doesn't define any directives, this clears this request's
     * cache-control headers.
     */
    open fun cacheControl(cacheControl: CacheControl): Builder {
      val value = cacheControl.toString()

```java
/** Dangerous interceptor that rewrites the server's cache-control header. */
private static final Interceptor REWRITE_CACHE_CONTROL_INTERCEPTOR = new Interceptor() {

    taskFaker.runNextTask()

    // The rebuild is retried on cache hits and on cache edits.
    val snapshot = cache["b"]!!
    snapshot.close()
    assertThat(cache.edit("d")).isNull()
    assertThat(taskFaker.isIdle()).isFalse()

    // On cache misses, no retry job is queued.
    assertThat(cache["c"]).isNull()
    assertThat(taskFaker.isIdle()).isFalse()

        }).orElse(StringUtil.EMPTY_STRINGS);
    }

    /**
     * Retrieves or creates the result document IDs cache from the session.
     * The cache is implemented as an LRU map to limit memory usage.
     *
     * @param session the HTTP session
     * @return the result document IDs cache map
     */
    private Map<String, String[]> getResultDocIdsCache(final HttpSession session) {

    protected int count = 1;

    /**
     * Cache for storing crawling configurations to improve performance.
     */
    protected Cache<String, CrawlingConfig> crawlingConfigCache;

    /**
     * Initializes the CrawlingConfigHelper by setting up the crawling configuration cache.
     * This method is called automatically after the bean construction is complete.

		if len(dui.BucketsUsage) > 0 {
			internalLogOnceIf(GlobalContext, fmt.Errorf("unable to retrieve usage information for bucket: %s, relying on older value cached in-memory: err(%v)", bucket, err), "bucket-usage-cache-"+bucket)
		} else {

    a bug where a shared connection pool did not guarantee shared connections in some cases.
 *  Fix: Prefer the server's response body on all conditional cache misses. Previously we would
    return the cached response's body if it had a newer `Last-Modified` date.
 *  Fix: Update the stored timestamp on conditional cache hits.
 *  New: Optimized HTTP/2 request header encoding. More headers are HPACK-encoded and string
    literals are now Huffman-encoded.

		t.Fatalf("deserialize LastUpdate mismatch\nwant: %+v\ngot:  %+v", want, got)
	}
	if len(want.Cache) != len(got.Cache) {
		t.Errorf("deserialize mismatch length\nwant: %+v\ngot:  %+v", len(want.Cache), len(got.Cache))
	}
	for wkey, wval := range want.Cache {
		gotv := got.Cache[wkey]
		if !equalAsJSON(gotv, wval) {
			t.Errorf("deserialize mismatch, key %v\nwant: %#v\ngot:  %#v", wkey, wval, gotv)
		}

        } catch (final Exception e) {
            return url;
        }
    }

    /**
     * Gets the character encoding for a parent URL from cache or data service.
     * Caches encoding information to improve performance on subsequent requests.
     *
     * @param parentUrl the parent URL to get encoding for
     * @param sessionId the session ID for the crawling session

	// returned by these functions must be present in the `Descriptors` list.
	loader       MetricsLoaderFn
	bucketLoader BucketMetricsLoaderFn

	// Cache for all metrics groups. Set via `.SetCache` method.
	cache *metricsCache

	// managed values follow:

	// map of metric descriptors by metric name.
	descriptorMap map[MetricName]MetricDescriptor