protected function atLeastOneExport( array $chapters ) {

		foreach ( $chapters as $key => $val ) {
			if ( is_array( $val ) ) {
				$found = $this->atLeastOneExport( $val );
				if ( $found ) {
					return true;
				} else {
					continue;
				}
			} elseif ( 'export' === (string) $key && $val ) {
				return true;
			}
		}

		return false;
	}