* exception.
   *
   * @throws IllegalStateException when the call has already been executed.
   */
  fun enqueue(responseCallback: Callback)

  /** Cancels the request, if possible. Requests that are already complete cannot be canceled. */
  fun cancel()

  /**
   * Returns true if this call has been either [executed][execute] or [enqueued][enqueue]. It is an

With fast fallback, OkHttp attempts to connect to multiple web servers concurrently. It keeps whichever route connects first and cancels all of the others. Its rules are:

 * Prefer to alternate IP addresses from different address families, (IPv6 / IPv4), starting with IPv6.
 * Don't start a new attempt until 250 ms after the most recent attempt was started.

 *  New: Upgrade to Okio 1.17.3. If you're on Kotlin-friendly Okio 2.x this release requires 2.2.2
    or newer.

    ```kotlin
    implementation("com.squareup.okio:okio:1.17.3")
    ```

 *  Fix: Don't miss cancels when sending HTTP/2 request headers.
 *  Fix: Don't miss whole operation timeouts when calls redirect.
 *  Fix: Don't leak connections if web sockets have malformed responses or if `onOpen()` throws.

      // This guarantees a deterministic sequence when handling the canceled request:
      // 1. Server reads request and dequeues first response
      // 2. Client cancels request
      // 3. Server tries to send response on the canceled stream
      // Otherwise, there is no guarantee for the sequence. For example, the server may use the

    )
  }

  override fun connectTcp(): ConnectResult {
    check(rawSocket == null) { "TCP already connected" }

    var success = false

    // Tell the call about the connecting call so async cancels work.
    user.addPlanToCancel(this)
    try {
      user.connectStart(route)

      connectSocket()
      success = true
      return ConnectResult(plan = this)
    } catch (e: IOException) {

Liu, Chen Guoyin, chenchc, chengchingwen, chie8842, Christian Hansen, Christoph
Boeddeker, Christopher Yeh, Clayne Robison, Coady, Patrick, crafet, csukuangfj,
ctiijima, Dan Jarvis, Dan Lazewatsky, Daniel Ingram, Daniel Rasmussen, Daniel
Salvadori, Dave Airlie, David Norman, Dayananda V, delock, Denis Khalikov, Deven
Desai, Dheeraj Rajaram Reddy, Diego Caballero, dmitrievanthony, Donovan Ong,

------------------------------------------------------------------------------
MIT

com.googlecode.plist:dd-plist
dd-plist - An open source library to parse and generate property lists
Copyright (C) 2016 Daniel Dreibrodt

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal

      // TODO: configure a timeout on the reader so that it doesn’t block forever.
      writer.goAway(lastGoodStreamId, statusCode, EMPTY_BYTE_ARRAY)
    }
  }

  /**
   * Closes this connection. This cancels all open streams and unanswered pings. It closes the
   * underlying input and output streams and shuts down internal task queues.
   */
  override fun close() {
    close(ErrorCode.NO_ERROR, ErrorCode.CANCEL, null)
  }

  // Valid values are:
  //
  // - "Allow" (default): allows CronJobs to run concurrently;
  // - "Forbid": forbids concurrent runs, skipping next run if previous run hasn't finished yet;
  // - "Replace": cancels currently running job and replaces it with a new one
  // +optional
  optional string concurrencyPolicy = 3;

  // This flag tells the controller to suspend subsequent executions, it does

    // our connection coalescing requirements are met. See also:
    // https://hpbn.co/optimizing-application-delivery/#eliminate-domain-sharding
    // https://daniel.haxx.se/blog/2016/08/18/http2-connection-coalescing/

    // 1. This connection must be HTTP/2.
    if (http2Connection == null) return false

    // 2. The routes must share an IP address.