* The value is, e.g.  <br>
     * comment: Integer-type fields for admin in the index.
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getIndexAdminIntegerFields();

    /**
     * Get the value for the key 'index.admin.integer.fields' as {@link Integer}. <br>
     * The value is, e.g.  <br>
     * comment: Integer-type fields for admin in the index.