*           }
 *         });
 * }
 *
 * <p>Or equivalently,
 *
 * {@snippet :
 * // In real life this would come from a command-line flag or config file
 * String spec = "maximumSize=10000,expireAfterWrite=10m";
 *
 * LoadingCache<Key, Graph> graphs = CacheBuilder.from(spec)
 *     .removalListener(MY_LISTENER)
 *     .build(
 *         new CacheLoader<Key, Graph>() {

	// of size = baseInterval.
	//
	// For example:
	//
	//    - if baseInterval=10s, then 5s <= waitInterval() < 15s
	//
	//    - if baseInterval=10m, then 5m <= waitInterval() < 15m
	waitInterval := func() time.Duration {
		// Calculate a random value such that 0 <= value < baseInterval
		randAmt := time.Duration(r.Float64() * float64(baseInterval))