checkNotNull(value);
    Timestamped<V> oldValue = cachingHashMap.put(key, new Timestamped<V>(value, ticker));
    if (oldValue == null) {
      return null;
    }
    alertListenerIfPresent(key, oldValue.getValue(), RemovalCause.REPLACED);
    return oldValue.getValue();
  }

  @CanIgnoreReturnValue
  @Override
  public V remove(Object key) {
    Timestamped<V> stamped = cachingHashMap.remove(key);

        protected String getUrl() {
            if (url != null) {
                return url;
            }
            return id;
        }
    }

    /**
     * Statistics data object that stores timestamped events and maintains reference counting.
     * Extends LinkedHashMap to store event names mapped to their timestamps.
     * Includes reference counting for multi-threaded access tracking.
     */