val headers =
      Headers.Builder()
        .add(
          "WWW-Authenticate",
          "Digest realm=\"myrealm\", nonce=\"fjalskdflwejrlaskdfjlaskdjflaks" +
            "jdflkasdf\", qop=\"auth\", stale=\"FALSE\"",
        )
        .build()
    val challenges = headers.parseChallenges("WWW-Authenticate")
    assertThat(challenges.size).isEqualTo(1)
    assertThat(challenges[0].scheme).isEqualTo("Digest")

_2020-04-06_

**This release fixes a severe bug where OkHttp incorrectly detected and recovered from unhealthy
connections.** Stale or canceled connections were incorrectly attempted when they shouldn't have
been, leading to rare cases of infinite retries. Please upgrade to this release!

 *  Fix: don't return stale DNS entries in `DnsOverHttps`. We were caching DNS results indefinitely

 * both.
 *
 * Selecting a cache strategy may add conditions to the request (like the "If-Modified-Since" header
 * for conditional GETs) or warnings to the cached response (if the cached data is potentially
 * stale).
 */
class CacheStrategy internal constructor(
  /** The request to send on the network, or null if this call doesn't use the network. */
  val networkRequest: Request?,

        .minFresh(3.seconds)
        .onlyIfCached()
        .noTransform()
        .immutable()
        .build()
    assertThat(cacheControl.toString()).isEqualTo(
      "no-cache, no-store, max-age=1, max-stale=2, min-fresh=3, only-if-cached, no-transform, immutable",
    )
    assertThat(cacheControl.noCache).isTrue()
    assertThat(cacheControl.noStore).isTrue()
    assertThat(cacheControl.maxAgeSeconds).isEqualTo(1)

        .header("Cache-Control", "max-stale=180")
        .build()
    val response = client.newCall(request).execute()
    assertThat(response.body.string()).isEqualTo("A")
    assertThat(response.header("Warning")).isEqualTo(
      "110 HttpURLConnection \"Response is stale\"",
    )
  }

  @Test
  fun requestMaxStaleDirectiveWithNoValue() {
    // Add a stale response to the cache.
    server.enqueue(

        .minFresh(3, TimeUnit.SECONDS)
        .onlyIfCached()
        .noTransform()
        .immutable()
        .build()
    assertThat(cacheControl.toString()).isEqualTo(
      "no-cache, no-store, max-age=1, max-stale=2, min-fresh=3, only-if-cached, " +
        "no-transform, immutable",
    )
    assertThat(cacheControl.noCache).isTrue()
    assertThat(cacheControl.noStore).isTrue()
    assertThat(cacheControl.maxAgeSeconds).isEqualTo(1)

        if (isPrivate) append("private, ")
        if (isPublic) append("public, ")
        if (mustRevalidate) append("must-revalidate, ")
        if (maxStaleSeconds != -1) append("max-stale=").append(maxStaleSeconds).append(", ")
        if (minFreshSeconds != -1) append("min-fresh=").append(minFreshSeconds).append(", ")
        if (onlyIfCached) append("only-if-cached, ")

  private var mostRecentRebuildFailed: Boolean = false

  /**
   * To differentiate between old and current snapshots, each entry is given a sequence number each
   * time an edit is committed. A snapshot is stale if its sequence number is not equal to its
   * entry's sequence number.
   */
  private var nextSequenceNumber: Long = 0

  private val cleanupQueue = taskRunner.newQueue()
  private val cleanupTask =

 *   // The resource was cached! Show it.
 * } else {
 *   // The resource was not cached.
 * }
 * ```
 *
 * This technique works even better in situations where a stale response is better than no response.
 * To permit stale cached responses, use the `max-stale` directive with the maximum staleness in
 * seconds:
 *
 * ```java
 * Request request = new Request.Builder()
 *     .cacheControl(new CacheControl.Builder()

  private fun getCacheOnlyResponse(request: Request): Response? {
    if (client.cache != null) {
      try {
        // Use the cache without hitting the network first
        // 504 code indicates that the Cache is stale
        val onlyIfCached =
          CacheControl.Builder()
            .onlyIfCached()
            .build()

        var cacheUrl = request.url

        val cacheRequest =