* an entry to be loaded, and the loading completes successfully. In contrast to {@link
     * #recordMisses}, this method should only be called by the loading thread.
     *
     * @param loadTime the number of nanoseconds the cache spent computing or retrieving the new
     *     value
     */
    @SuppressWarnings("GoodTime") // should accept a java.time.Duration
    void recordLoadSuccess(long loadTime);

    /**

        .matches(
            "[^\\[]+\\[status=PENDING, info=\\[cause=\\[Because this test isn't done\\]\\]\\]");
    TimeoutException e = assertThrows(TimeoutException.class, () -> testFuture.get(1, NANOSECONDS));
    assertThat(e).hasMessageThat().contains("1 nanoseconds");
    assertThat(e).hasMessageThat().contains("Because this test isn't done");
  }

  public void testToString_completesDuringToString() throws Exception {

import static com.google.common.util.concurrent.TestPlatform.verifyGetOnPendingFuture;
import static com.google.common.util.concurrent.TestPlatform.verifyTimedGetOnPendingFuture;
import static java.util.concurrent.TimeUnit.NANOSECONDS;
import static java.util.concurrent.TimeUnit.SECONDS;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;

import static com.google.common.util.concurrent.Platform.restoreInterruptIfIsInterruptedException;
import static java.util.Objects.requireNonNull;
import static java.util.concurrent.TimeUnit.NANOSECONDS;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;

import static com.google.common.testing.SerializableTester.reserialize;
import static com.google.common.truth.Truth.assertThat;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import static java.util.concurrent.TimeUnit.NANOSECONDS;
import static java.util.concurrent.TimeUnit.SECONDS;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;

import static com.google.common.testing.SerializableTester.reserialize;
import static com.google.common.truth.Truth.assertThat;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import static java.util.concurrent.TimeUnit.NANOSECONDS;
import static java.util.concurrent.TimeUnit.SECONDS;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;

    lastTimestampNs = result.timestampNs

    if (eventClass != null) {
      assertThat(result).isInstanceOf(eventClass)
    }

    if (elapsedMs != -1L) {
      assertThat(
        TimeUnit.NANOSECONDS
          .toMillis(actualElapsedNs)
          .toDouble(),
      ).isCloseTo(elapsedMs.toDouble(), 100.0)
    }

    return result
  }

  fun recordedEventTypes() = eventSequence.map { it::class }

    val startNanos = System.nanoTime()
    while (webSocket.receivedPongCount() < 3) {
      Thread.sleep(50)
    }
    val elapsedUntilPong3 = System.nanoTime() - startNanos
    assertThat(TimeUnit.NANOSECONDS.toMillis(elapsedUntilPong3).toDouble())
      .isCloseTo(1500.0, 250.0)

    // The client pinged the server 3 times, and it has ponged back 3 times.
    assertThat(webSocket.sentPingCount()).isEqualTo(3)

xlHeaderVersion version == 1:

```
//msgp:tuple xlMetaV2VersionHeader
type xlMetaV2VersionHeader struct {
 VersionID [16]byte  // Version UUID, raw.
 ModTime   int64     // Unix nanoseconds.
 Signature [4]byte   // Signature of metadata.
 Type      uint8     // Type if the version
 Flags     uint8
}
```

The following flags are defined:

```
const (
 FreeVersion = 1 << 0

    call: Call,
    cachedResponse: Response,
  ) {
    logWithTime("cacheConditionalHit: $cachedResponse")
  }

  private fun logWithTime(message: String) {
    val timeMs = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startNs)
    logger.log("[$timeMs ms] $message")
  }

  open class Factory
    @JvmOverloads
    constructor(