require(cacheResponse == null) { "$name.cacheResponse != null" }
        require(priorResponse == null) { "$name.priorResponse != null" }
      }
    }

    open fun priorResponse(priorResponse: Response?) =
      apply {
        this.priorResponse = priorResponse
      }

    open fun trailers(trailersSource: TrailersSource): Builder =
      apply {

    val redirect: Boolean = response.isRedirect
    val networkResponse: Response? = response.networkResponse
    val cacheResponse: Response? = response.cacheResponse
    val priorResponse: Response? = response.priorResponse
    val challenges: List<Challenge> = response.challenges()
    val cacheControl: CacheControl = response.cacheControl
    val sentRequestAtMillis: Long = response.sentRequestAtMillis

    val sanUrl =
      url
        .newBuilder()
        .host("san.com")
        .build()
    execute(sanUrl).use { response ->
      assertThat(response.code).isEqualTo(200)
      assertThat(response.priorResponse!!.code).isEqualTo(421)
      assertThat(response.body.string()).isEqualTo("after misdirect")
    }
    val c0e0 = server.takeRequest()
    assertThat(c0e0.connectionIndex).isEqualTo(0)

    }
    ```

    This above code relies on this `responseCount` extension val:

    ```kotlin
    val Response.responseCount: Int
      get() = generateSequence(this) { it.priorResponse }.count()
    ```
=== ":material-language-java: Java"
    ```java
      private final OkHttpClient client;

      public Authenticate() {
        client = new OkHttpClient.Builder()

      ),
    )
    server.enqueue(MockResponse(body = "C"))
    executeSynchronously("/a")
      .assertCode(200)
      .assertBody("C")
      .priorResponse()
      .assertCode(302)
      .assertHeader("Test", "Redirect from /b to /c")
      .priorResponse()
      .assertCode(301)
      .assertHeader("Test", "Redirect from /a to /b")

    // New connection.

	public final fun newBuilder ()Lokhttp3/Response$Builder;
	public final fun peekBody (J)Lokhttp3/ResponseBody;
	public final fun peekTrailers ()Lokhttp3/Headers;
	public final fun priorResponse ()Lokhttp3/Response;
	public final fun protocol ()Lokhttp3/Protocol;
	public final fun receivedResponseAtMillis ()J
	public final fun request ()Lokhttp3/Request;
	public final fun sentRequestAtMillis ()J

    type declaration was nullable to support rare cases like the body on `Response.cacheResponse`,
    `Response.networkResponse`, and `Response.priorResponse`. In such cases the body is now
    non-null, but attempts to read its content will fail.
 *  New: Kotlin-specific APIs for request tags. Kotlin language users can lookup tags with a type

	public final fun newBuilder ()Lokhttp3/Response$Builder;
	public final fun peekBody (J)Lokhttp3/ResponseBody;
	public final fun peekTrailers ()Lokhttp3/Headers;
	public final fun priorResponse ()Lokhttp3/Response;
	public final fun protocol ()Lokhttp3/Protocol;
	public final fun receivedResponseAtMillis ()J
	public final fun request ()Lokhttp3/Request;
	public final fun sentRequestAtMillis ()J

    val challengeResponse = authenticator.responses[0]
    assertThat(
      challengeResponse.request.url
        .toUrl()
        .path,
    ).isEqualTo("/b")
    val redirectedBy = challengeResponse.priorResponse
    assertThat(
      redirectedBy!!
        .request.url
        .toUrl()
        .path,
    ).isEqualTo("/a")
  }

  @Test
  fun attemptAuthorization20Times() {