protected function setup_tabs($options = array()) {
        global $CFG, $PAGE;
        $groupmode = groups_get_activity_groupmode($this->cm);

        if (empty($CFG->usecomments) || !has_capability('mod/wiki:viewcomment', $PAGE->context)){
            unset($this->tabs['comments']);
        }

        if (!has_capability('mod/wiki:editpage', $PAGE->context)){
            unset($this->tabs['edit']);
        }

        if ($groupmode and $groupmode == VISIBLEGROUPS) {
            $currentgroup = groups_get_activity_group($this->cm);
            $manage = has_capability('mod/wiki:managewiki', $this->modcontext);
            $edit = has_capability('mod/wiki:editpage', $PAGE->context);
            if (!$manage and !($edit and groups_is_member($currentgroup))) {
                unset($this->tabs['edit']);
            }
        }

        if (empty($options)) {
            $this->tabs_options = array('activetab' => substr(get_class($this), 10));
        } else {
            $this->tabs_options = $options;
        }

    }