* @return The value of found property. (NotNull: if not found, exception but basically no way)
     * @throws NumberFormatException When the property is not integer.
     */
    Integer getIndexDocumentCrawlerDataNumberOfReplicasAsInteger();

    /**
     * Get the value for the key 'index.document.crawler.filter.number_of_replicas'. <br>
     * The value is, e.g. 1 <br>