/**
   * Called when the request could not be executed due to cancellation, a connectivity problem or
   * timeout. Because networks can fail during an exchange, it is possible that the remote server
   * accepted the request before the failure.
   */
  fun onFailure(
    call: Call,
    e: IOException,
  )

  /**
   * Called when the HTTP response was successfully returned by the remote server. The callback may

    when OkHttp retrieves ALPN state on a closed connection.


## Version 4.9.3

_2021-11-21_

 *  Fix: Don't fail HTTP/2 responses if they complete before a `RST_STREAM` is sent.


## Version 4.9.2

_2021-09-30_

 *  Fix: Don't include potentially-sensitive header values in `Headers.toString()` or exceptions.

  private var timeoutEarlyExit = false

  /**
   * This is the same value as [exchange], but scoped to the execution of the network interceptors.
   * The [exchange] field is assigned to null when its streams end, which may be before or after the
   * network interceptors return.
   */
  internal var interceptorScopedExchange: Exchange? = null
    private set

 * limitations under the License.
 */
package okhttp3

import java.io.IOException
import okhttp3.internal.authenticator.JavaNetAuthenticator

/**
 * Performs either **preemptive** authentication before connecting to a proxy server, or
 * **reactive** authentication after receiving a challenge from either an origin web server or proxy
 * server.
 *
 * ## Preemptive Authentication
 *

    // appendCodePoint(). The Punycode algorithm processes code points in increasing code-point
    // order, not in increasing index order.
    val codePoints = mutableListOf<Int>()

    // consume all code points before the last delimiter (if there is one)
    //  and copy them to output, fail on any non-basic code point
    val lastDelimiter = string.lastIndexOf('-', limit)
    if (lastDelimiter >= pos) {
      while (pos < lastDelimiter) {

  }

  // All done. If compression happened, we need to move bytes to the right place in the
  // address. Here's a sample:
  //
  //      input: "1111:2222:3333::7777:8888"
  //     before: { 11, 11, 22, 22, 33, 33, 00, 00, 77, 77, 88, 88, 00, 00, 00, 00  }
  //   compress: 6
  //          b: 10
  //      after: { 11, 11, 22, 22, 33, 33, 00, 00, 00, 00, 00, 00, 77, 77, 88, 88 }
  //

   * true when removing a connection from the pool; otherwise a racing caller might get it from the
   * pool when it shouldn't. Symmetrically, this must always be checked before returning a
   * connection from the pool.
   *
   * Once true this is always true. Guarded by this.
   */
  var noNewExchanges = false

  /**

    // We know that a fresh connection was created if the server recorded a request with sequence
    // number 0. Since the client may have attempted to reuse the broken connection just before
    // creating a fresh connection, the server may have recorded 2 requests at this point. The order
    // of recording is non-deterministic.
    val requestAfter = server.takeRequest()
    assertThat(

      payload.writeByte('0'.code)
    }
    serverWriter.writeMessageFrame(OPCODE_BINARY, payload.snapshot())

    // Write directly to the unbuffered sink. This ensures it will become single frame.
    assertData("827e") // 'e' == 4-byte follow-up length.
    assertData(format("%04X", payload.completeSegmentByteCount()))
    assertData(payload.readByteString())
  }

   *
   * This is typically invoked immediately before bytes are returned to the application. If the
   * response body is empty this is invoked immediately before returning that to the application.
   *
   * If the application closes the response body before attempting a read, this is invoked at the
   * time it is closed.
   *