* if a socket connection is being established, that is terminated.
   */
  override fun cancel() {
    if (canceled) return // Already canceled.

    canceled = true
    exchange?.cancel()
    for (plan in plansToCancel) {
      plan.cancel()
    }

    eventListener.canceled(this)
  }

  override fun isCanceled(): Boolean = canceled

  private val http2Stream: Http2Stream,
) : Stream {
  override val requestBody = http2Stream.getSource().buffer()
  override val responseBody = http2Stream.getSink().buffer()

  override fun cancel() {
    http2Stream.closeLater(ErrorCode.CANCEL)
  }

   * the event source has already been closed or canceled.
   */
  fun cancel()

  fun interface Factory {
    /**
     * Creates a new event source and immediately returns it. Creating an event source initiates an
     * asynchronous process to connect the socket. Once that succeeds or fails, `listener` will be
     * notified. The caller must cancel the returned event source when it is no longer in use.
     */
    fun newEventSource(

        exchange.bodyComplete<IOException?>(-1L, responseDone = true, requestDone = true, e = null)
      }

      override fun cancel() {
        exchange.cancel()
      }
    }
  }

  override fun route(): Route = route

  override fun cancel() {
    // Close the raw socket so we don't end up doing synchronous I/O.
    rawSocket?.closeQuietly()
  }

@ExperimentalCoroutinesApi // resume with a resource cleanup.
suspend fun Call.executeAsync(): Response =
  suspendCancellableCoroutine { continuation ->
    continuation.invokeOnCancellation {
      this.cancel()
    }
    this.enqueue(
      object : Callback {
        override fun onFailure(
          call: Call,
          e: IOException,
        ) {
          continuation.resumeWithException(e)
        }

 * includes both natural exceptions such as unreachable servers, as well as synthetic exceptions
 * when responses are of an unexpected type or cannot be decoded.
 *
 * Other exception types cancel the current call:
 *
 *  * For synchronous calls made with [Call.execute], the exception is propagated to the caller.
 *
 *  * For asynchronous calls made with [Call.enqueue], an [IOException] is propagated to the caller

    }
    ```

 *  New: Upgrade to Okio 2.4.3.

    ```kotlin
    implementation("com.squareup.okio:okio:2.4.3")
    ```

 *  Fix: Limit retry attempts for HTTP/2 `REFUSED_STREAM` and `CANCEL` failures.
 *  Fix: Retry automatically when incorrectly sharing a connection among multiple hostnames. OkHttp
    shares connections when hosts share both IP addresses and certificates, such as `squareup.com`

    assertThat(readAscii(in1, 5)).isEqualTo("ABCDE")
    in1.close()
    call1.cancel()
    val call2 = client.newCall(newRequest("/"))
    val response2 = call2.execute()
    val in2 = response2.body.byteStream()
    assertThat(readAscii(in2, 5)).isEqualTo("LMNOP")
    in2.close()
    call2.cancel()
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(0)
    // Connection is pooled!

          this,
          IllegalStateException("Invalid content-type: ${body.contentType()}"),
          response,
        )
        return
      }

      // This is a long-lived response. Cancel full-call timeouts.
      call?.timeout()?.cancel()

      // Replace the body with a stripped one so the callbacks can't see real data.
      val response = response.stripBody()

      val reader = ServerSentEventReader(body.source(), this)

          .bodyDelay(5, TimeUnit.SECONDS)
          .body("abc")
          .build(),
      )

      val call = client.newCall(request)

      try {
        call.executeAsync().use {
          call.cancel()
          withContext(Dispatchers.IO) {
            it.body.string()
          }
          fail("No expected to get response")
        }
      } catch (ioe: IOException) {
        // expected
      }