Custom bbp_list_forums bbPress

    public function custom_bbp_list_forums( $args = '' ) {

        // Define used variables
        $output = $sub_forums = $topic_count = $reply_count = $counts = '';
        $i = 0;
        $count = array();

        // Defaults and arguments
        $defaults = array (
            'before'            => '<ul class="bbp-forums-list">',
            'after'             => '</ul>',
            'link_before'       => '<li class="bbp-forum">',
            'link_after'        => '</li>',
            'count_before'      => ' (',
            'count_after'       => ')',
            'count_sep'         => ', ',
            'separator'         => ', ',
            'forum_id'          => '',
            'show_topic_count'  => true,
            'show_reply_count'  => true,
            'show_freshness_link'  => true,
        );
        $r = bbp_parse_args( $args, $defaults, 'list_forums' );
        extract( $r, EXTR_SKIP );

        // Bail if there are no subforums
        if ( !bbp_get_forum_subforum_count( $forum_id ) )
            return;

        // Loop through forums and create a list
        $sub_forums = bbp_forum_get_subforums( $forum_id );
        if ( !empty( $sub_forums ) ) {

            // Total count (for separator)
            $total_subs = count( $sub_forums );
            foreach ( $sub_forums as $sub_forum ) {
                $i++; // Separator count

                // Get forum details
                $count     = array();
                $show_sep  = $total_subs > $i ? $separator : '';
                $permalink = bbp_get_forum_permalink( $sub_forum->ID );
                $title     = bbp_get_forum_title( $sub_forum->ID );

                // Show topic count
                if ( !empty( $show_topic_count ) && !bbp_is_forum_category( $sub_forum->ID ) ) {
                    $count['topic'] = bbp_get_forum_topic_count( $sub_forum->ID );
                }

                // Show reply count
                if ( !empty( $show_reply_count ) && !bbp_is_forum_category( $sub_forum->ID ) ) {
                    $count['reply'] = bbp_get_forum_reply_count( $sub_forum->ID );
                }

                // Counts to show
                if ( !empty( $count ) ) {
                    $counts = $count_before . implode( $count_sep, $count ) . $count_after;
                }

                if ( !empty( $show_freshness_link ) ) {
                    $freshness_link = "<div class='freshness-forum-link'>" . BBP_Default::custom_get_last_poster_block( $sub_forum->ID ) . "</div>";
                }

                // Build this sub forums link
                if ($i % 2) { $class = "odd-forum-row"; } else { $class = "even-forum-row"; }
                $output .= "<li class='{$class}'><ul>" . $link_before . '<a href="' . $permalink . '" class="bbp-forum-link">' . $title . '</a>' . $counts . $freshness_link . $link_after . "</ul></li>";
            }

            // Output the list
            echo apply_filters( 'bbp_list_forums', $before . $output . $after, $args );
        }
    }

// Then I call the function like this
BBP_Default::custom_bbp_list_forums( array (
        'before'            => '<ul class="bbp-forums-list">',
        'after'             => '</ul>',
        'link_before'       => '<li class="bbp-forum">',
        'link_after'        => '</li>',
        'count_before'      => '<div class="topic-reply-counts">Topics: ',
        'count_after'       => '</div>',
        'count_sep'         => '<br />Posts: ',
        'separator'         => '<div style="clear:both;"></div>',
        'forum_id'          => '',
        'show_topic_count'  => true,
        'show_reply_count'  => true,
        'show_freshness_link' => true,
    ));