?: throw IOException("Failed to authenticate with proxy")

          if ("close".equals(response.header("Connection"), ignoreCase = true)) {
            return nextRequest
          }
        }

        else -> throw IOException("Unexpected response code for CONNECT: ${response.code}")
      }
    }
  }

  /**

    ```

 *  New: Make the content-type header optional for request bodies.
 *  New: `Response.isSuccessful()` is a convenient API to check response codes.
 *  New: The response body can now be read outside of the callback. Response
    bodies must always be closed, otherwise they will leak connections!
 *  New: APIs to create multipart request bodies (`MultipartBuilder`) and form

  }

  @Test
  fun response() {
    val response: Response = Response.Builder().build()
    val request: Request = response.request
    val protocol: Protocol = response.protocol
    val code: Int = response.code
    val successful: Boolean = response.isSuccessful
    val message: String = response.message
    val handshake: Handshake? = response.handshake

    val call = client.newCall(request)
    val response =
      Response.Builder().request(request).code(200).message("").protocol(Protocol.HTTP_2)
        .build()
    val listener = loggingEventListenerFactory.create(call)
    listener.cacheConditionalHit(call, response)
    listener.cacheHit(call, response)
    listener.cacheMiss(call)
    listener.satisfactionFailure(call, response)
    logRecorder

      var response: Response
      var closeActiveExchange = true
      try {
        if (call.isCanceled()) {
          throw IOException("Canceled")
        }

        try {
          response = realChain.proceed(request)
          newRoutePlanner = true
        } catch (e: IOException) {
          // An attempt to communicate with a server failed. The request may have been sent.

  }

  @Throws(IOException::class)
  internal fun checkUpgradeSuccess(
    response: Response,
    exchange: Exchange?,
  ) {
    if (response.code != 101) {
      throw ProtocolException(
        "Expected HTTP 101 response but was '${response.code} ${response.message}'",
      )
    }

    val headerConnection = response.header("Connection")
    if (!"Upgrade".equals(headerConnection, ignoreCase = true)) {

import okhttp3.RequestBody
import okhttp3.Response
import okhttp3.ResponseBody
import okhttp3.internal.http2.Header
import okio.Buffer
import okio.BufferedSource
import okio.Source

@JvmField
internal val EMPTY_HEADERS: Headers = commonEmptyHeaders

@JvmField
internal val EMPTY_REQUEST: RequestBody = commonEmptyRequestBody

@JvmField
internal val EMPTY_RESPONSE: ResponseBody = commonEmptyResponse

          .build(),
      )
    call.execute().use { response ->
      assertThat(response.headers)
        .isEqualTo(headersOf("h1", "v1", "h2", "v2"))
      val responseBody = response.body.source()
      assertThat(responseBody.readUtf8(2)).isEqualTo("ok")
      assertThat(responseBody.exhausted()).isTrue()
      assertThat(response.trailers()).isEqualTo(headersOf("trailers", "boom"))
    }

    val request = Request(
      url = "https://cash.app/".toHttpUrl(),
    )
    ```

 *  New: `Response.body` is now non-null. This was generally the case in OkHttp 4.x, but the Kotlin
    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.

      val response =
        Response.Builder()
          .code(101)
          .message("OK")
          .request(Request.Builder().url(url).build())
          .headers(responseHeaders!!)
          .protocol(Protocol.HTTP_1_1)
          .build()
      webSocket =
        RealWebSocket(
          taskFaker.taskRunner,
          response.request,
          listener,
          random!!,