code: public static <K, V> CacheEvent<K, V> expiry(K expiredKey, V expiredValue, Cache<K, V> source) {
      return new ExpiryEvent<>(expiredKey, expiredValue, source);
    }
docs: Creates an {@link EventType#EXPIRED expired} {@link CacheEvent}.
  
  @param expiredKey the key for which the mapping expired
  @param expiredValue the expired value
  @param source the event source
  @param <K> the key type
  @param <V> the value type
  
  @return an expiry cache event