}

    /**
     * Sets the cache expiration time after write in milliseconds.
     *
     * @param cacheExpireAfterWrite the expiration time in milliseconds
     */
    public void setCacheExpireAfterWrite(final long cacheExpireAfterWrite) {
        this.cacheExpireAfterWrite = cacheExpireAfterWrite;
    }

    /**
     * Key object for statistics tracking that contains an identifier and optional URL.