[time.Timer] and [time.Ticker].

First, `Timer`s and `Ticker`s that are no longer referred to by the program
become eligible for garbage collection immediately, even if their
`Stop` methods have not been called.
Earlier versions of Go did not collect unstopped `Timer`s until after
they had fired and never collected unstopped `Ticker`s.

Second, the timer channel associated with a `Timer` or `Ticker` is

            return Futures.immediateFuture(two);
          }
        };

    LoadingCache<Object, Object> cache =
        CacheBuilder.newBuilder()
            .recordStats()
            .ticker(ticker)
            .refreshAfterWrite(1, MILLISECONDS)
            .build(loader);
    Object key = new Object();
    CacheStats stats = cache.stats();
    assertEquals(0, stats.missCount());

  private static class Timestamped<V> {
    private final V value;
    private final Ticker ticker;
    private long writeTimestamp;
    private long accessTimestamp;

    public Timestamped(V value, Ticker ticker) {
      this.value = checkNotNull(value);
      this.ticker = checkNotNull(ticker);
      this.writeTimestamp = ticker.read();
      this.accessTimestamp = this.writeTimestamp;
    }

    checkNotNull(ticker);
    expireEntries(toLocalCache(cache), expiringTime, ticker);
  }

  static void expireEntries(LocalCache<?, ?> cchm, long expiringTime, FakeTicker ticker) {

    for (Segment<?, ?> segment : cchm.segments) {
      drainRecencyQueue(segment);
    }

    ticker.advance(2 * expiringTime, TimeUnit.MILLISECONDS);

// volume, path and operation ID.
func (n *nsLockMap) NewNSLock(lockers func() ([]dsync.NetLocker, string), volume string, paths ...string) RWLocker {
	opsID := mustGetUUID()
	if n.isDistErasure {
		drwmutex := dsync.NewDRWMutex(&dsync.Dsync{
			GetLockers: lockers,
			Timeouts:   dsync.DefaultTimeouts,
		}, pathsJoinPrefix(volume, paths...)...)

   * @throws IllegalStateException if a ticker was already set
   */
  @CanIgnoreReturnValue
  public CacheBuilder<K, V> ticker(Ticker ticker) {
    checkState(this.ticker == null);
    this.ticker = checkNotNull(ticker);
    return this;
  }

  Ticker getTicker(boolean recordsTime) {
    if (ticker != null) {
      return ticker;
    }
    return recordsTime ? Ticker.systemTicker() : NULL_TICKER;
  }

            return Futures.immediateFuture(two);
          }
        };

    LoadingCache<Object, Object> cache =
        CacheBuilder.newBuilder()
            .recordStats()
            .ticker(ticker)
            .refreshAfterWrite(1, MILLISECONDS)
            .build(loader);
    Object key = new Object();
    CacheStats stats = cache.stats();
    assertEquals(0, stats.missCount());

	String() string

	// Close closes any underlying connection to the service endpoint
	Close() error

	// Is the underlying connection online? (is always true for any local lockers)
	IsOnline() bool

	// Is the underlying locker local to this server?
	IsLocal() bool

		},
		{
			val:   0.79,
			label: labels[2],
		},
	}
	ticker := time.NewTicker(1 * time.Millisecond)
	defer ticker.Stop()
	for _, obs := range observations {
		// Send observations once every 1ms, to simulate delay between
		// observations. This is to test the channel based
		// synchronization used internally.
		select {
		case <-ticker.C:
			ttfbHist.With(prometheus.Labels{"api": obs.label}).Observe(obs.val)
		}

      this.maxWeight = maxWeight;
      this.weigher = weigher;
      this.concurrencyLevel = concurrencyLevel;
      this.removalListener = removalListener;
      this.ticker = (ticker == Ticker.systemTicker() || ticker == NULL_TICKER) ? null : ticker;
      this.loader = loader;
    }

    CacheBuilder<K, V> recreateCacheBuilder() {
      CacheBuilder<K, V> builder =
          CacheBuilder.newBuilder()