## Version 4.2.1

_2019-10-02_

 *  Fix: In 4.1.0 we introduced a performance regression that prevented connections from being
    pooled in certain situations. We have good test coverage for connection pooling but we missed
    this because it only occurs if you have proxy configured and you share a connection pool among
    multiple `OkHttpClient` instances.

    val snapshot = cache["b"]!!
    snapshot.close()
    assertThat(cache.edit("d")).isNull()
    assertThat(taskFaker.isIdle()).isFalse()

    // On cache misses, no retry job is queued.
    assertThat(cache["c"]).isNull()
    assertThat(taskFaker.isIdle()).isFalse()

    // Let the rebuild complete successfully.

   */
  fun enqueue(response: MockResponse) = (dispatcher as QueueDispatcher).enqueueResponse(response)

  /**
   * Starts the server on the loopback interface for the given port.
   *
   * @param port the port to listen to, or 0 for any available port. Automated tests should always
   * use port 0 to avoid flakiness when a specific port is unavailable.
   */
  @Throws(IOException::class)
  @JvmOverloads