val response1 = get(server.url("/a"))
    assertThat(response1.body.string()).isEqualTo("A")
    assertThat(response1.header("Allow")).isNull()
    assertThat((response1.receivedResponseAtMillis - t0).toDouble()).isCloseTo(0.0, 250.0)

    // A conditional cache hit updates the cache.
    Thread.sleep(500) // Make sure t0 and t1 are distinct.
    val t1 = System.currentTimeMillis()

as you say it.'

  `That's nothing to what I could say if I chose,' the Duchess
replied, in a pleased tone.

  `Pray don't trouble yourself to say it any longer than that,'
said Alice.

  `Oh, don't talk about trouble!' said the Duchess.  `I make you
a present of everything I've said as yet.'

  `A cheap sort of present!' thought Alice.  `I'm glad they don't

 * @author Bob Lee ({@code com.google.common.collect.MapMaker})
 * @author Doug Lea ({@code ConcurrentHashMap})
 */
@SuppressWarnings({
  "GoodTime", // lots of violations (nanosecond math)
  "nullness", // too much trouble for the payoff
})
@GwtCompatible(emulated = true)
// TODO(cpovirk): Annotate for nullness.
class LocalCache<K, V> extends AbstractMap<K, V> implements ConcurrentMap<K, V> {

  /*