return connection.socket()
      }
    }

    return null
  }

  private fun <E : IOException?> timeoutExit(cause: E): E {
    if (timeoutEarlyExit) return cause
    if (!timeout.exit()) return cause

    val e = InterruptedIOException("timeout")
    if (cause != null) e.initCause(cause)
    @Suppress("UNCHECKED_CAST") // E is either IOException or IOException?
    return e as E
  }

          coordinatorWakeUpAt = now + minDelayNanos
          try {
            backend.coordinatorWait(this@TaskRunner, minDelayNanos)
          } catch (_: InterruptedException) {
            // Will cause all tasks to exit unless more are scheduled!
            cancelAll()
          } finally {
            coordinatorWaiting = false
          }
        }
      }
    }
  }

   * request is transmitted. This is only interesting for duplex calls where the request and
   * response may be interleaved.
   *
   * Read this value only once for each enter/exit pair because its value can change.
   */
  private fun doReadTimeout() = !connection.client || sink.closed || sink.finished

  /**
   * A source that reads the incoming data frames of a stream. Although this class uses