}

  @Test fun testDigestChallengeWithTokenFormOfAuthParam() {
    val headers =
      Headers.Builder()
        .add("WWW-Authenticate", "Digest realm=myrealm").build()
    val challenges = headers.parseChallenges("WWW-Authenticate")
    assertThat(challenges.size).isEqualTo(1)
    assertThat(challenges[0].scheme).isEqualTo("Digest")

              return null // Give up, we've already attempted to authenticate.
            }

            println("Authenticating for response: $response")
            println("Challenges: ${response.challenges()}")
            val credential = Credentials.basic("jesse", "password1")
            return response.request.newBuilder()
              .header("Authorization", credential)
              .build()
          }

  /**
   * Returns the RFC 7235 authorization challenges appropriate for this response's code. If the
   * response code is 401 unauthorized, this returns the "WWW-Authenticate" challenges. If the
   * response code is 407 proxy unauthorized, this returns the "Proxy-Authenticate" challenges.
   * Otherwise this returns an empty list of challenges.
   *
   * If a challenge uses the `token68` variant instead of auth params, there is exactly one

 * challenge. The proxy authenticator may return either an authenticated request, or null to
 * connect without authentication.
 *
 * ```java
 * for (Challenge challenge : response.challenges()) {
 *   // If this is preemptive auth, use a preemptive credential.
 *   if (challenge.scheme().equalsIgnoreCase("OkHttp-Preemptive")) {

    route: Route?,
    response: Response,
  ): Request? {
    val challenges = response.challenges()
    val request = response.request
    val url = request.url
    val proxyAuthorization = response.code == 407
    val proxy = route?.proxy ?: Proxy.NO_PROXY

    for (challenge in challenges) {
      if (!"Basic".equals(challenge.scheme, ignoreCase = true)) {
        continue
      }

 */
fun Headers.parseChallenges(headerName: String): List<Challenge> {
  val result = mutableListOf<Challenge>()
  for (h in 0 until size) {
    if (headerName.equals(name(h), ignoreCase = true)) {
      val header = Buffer().writeUtf8(value(h))
      try {
        header.readChallengeHeader(result)
      } catch (e: EOFException) {
        Platform.get().log("Unable to parse challenge", Platform.WARN, e)
      }
    }
  }

A single HTTP call may require follow-up requests to be made to handle authentication challenges, redirects, and HTTP-layer timeouts. In such cases multiple connections, requests, and responses may be attempted. Follow-ups are another reason a single call may trigger multiple events of the same type.

 4. If it's a new route, it connects by building either a direct socket connection, a TLS tunnel (for HTTPS over an HTTP proxy), or a direct TLS connection. It does TLS handshakes as necessary. This step may be retried for tunnel challenges and TLS handshake failures.
 5. It sends the HTTP request and reads the response.

    return response.request.newBuilder()
      .addHeader(header, credential)
      .build()
  }

  private fun schemeMatches(response: Response): Boolean {
    if (scheme == null) return true
    return response.challenges().any { it.scheme.equals(scheme, ignoreCase = true) }
  }

 *
 *  * [TCP handshake][connectSocket]
 *  * Optional [CONNECT tunnels][connectTunnel]. When using an HTTP proxy to reach an HTTPS server
 *    we must send a `CONNECT` request, and handle authorization challenges from the proxy.
 *  * Optional [TLS handshake][connectTls].
 *
 * Each step may fail. If a retry is possible, a new instance is created with the next plan, which
 * will be configured differently.
 */
class ConnectPlan(