// Play it back.
    val connection = connect(peer)
    val pingAtNanos = System.nanoTime()
    connection.writePingAndAwaitPong()
    val elapsedNanos = System.nanoTime() - pingAtNanos
    assertThat(elapsedNanos).isGreaterThan(0L)
    assertThat(elapsedNanos).isLessThan(TimeUnit.SECONDS.toNanos(1))

    // Verify the peer received what was expected.
    val pingFrame = peer.takeFrame()