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

    /**
     * Get the value for the key 'index.admin.long.fields'. <br>
     * The value is, e.g. content_length,favorite_count,click_count <br>