get_lastcommentmodified example

|| ( empty( $this->query_vars['withoutcomments'] )
                    && ( ! empty( $this->query_vars['p'] )
                        || ! empty( $this->query_vars['name'] )
                        || ! empty( $this->query_vars['page_id'] )
                        || ! empty( $this->query_vars['pagename'] )
                        || ! empty( $this->query_vars['attachment'] )
                        || ! empty( $this->query_vars['attachment_id'] )
                    )
                )
            ) {
                $wp_last_modified_post    = mysql2date( $date_format, get_lastpostmodified( 'GMT' ), false );
                $wp_last_modified_comment = mysql2date( $date_format, get_lastcommentmodified( 'GMT' ), false );
                if ( strtotime( $wp_last_modified_post ) > strtotime( $wp_last_modified_comment ) ) {
                    $wp_last_modified = $wp_last_modified_post;
                } else {
                    $wp_last_modified = $wp_last_modified_comment;
                }
            } else {
                $wp_last_modified = mysql2date( $date_format, get_lastpostmodified( 'GMT' ), false );
            }

            if ( ! $wp_last_modified ) {
                $wp_last_modified = gmdate( $date_format );
            }