// The second byte of this request will be delayed by 750ms so we should time out after 250ms.
    val startNanos = System.nanoTime()
    bodySource.use {
      assertFailsWith<IOException> {
        bodySource.readByte()
      }.also { expected ->
        // Timed out as expected.
        val elapsedNanos = System.nanoTime() - startNanos
        val elapsedMillis = TimeUnit.NANOSECONDS.toMillis(elapsedNanos)