public static function delete_competency($id) {
        global $DB;
        static::require_enabled();
        $competency = new competency($id);

        // First we do a permissions check.
        require_capability('moodle/competency:competencymanage', $competency->get_context());

        $events = array();
        $competencyids = array(intval($competency->get('id')));
        $contextid = $competency->get_context()->id;
        $competencyids = array_merge(competency::get_descendants_ids($competency), $competencyids);
        if (!competency::can_all_be_deleted($competencyids)) {
            return false;
        }
        $transaction = $DB->start_delegated_transaction();

        try {

            // Reset the rule of the parent.
            $parent = $competency->get_parent();
            if ($parent) {
                $parent->reset_rule();
                $parent->update();
            }

            // Delete the competency separately so the after_delete event can be triggered.
            $competency->delete();

            // Delete the competencies.
            competency::delete_multiple($competencyids);

            // Delete the competencies relation.
            related_competency::delete_multiple_relations($competencyids);

            // Delete competency evidences.
            user_evidence_competency::delete_by_competencyids($competencyids);

            // Register the competencies deleted events.
            $events = \core\event\competency_deleted::create_multiple_from_competencyids($competencyids, $contextid);

        } catch (\Exception $e) {
            $transaction->rollback($e);
        }

        $transaction->allow_commit();
        // Trigger events.
        foreach ($events as $event) {
            $event->trigger();
        }

        return true;
    }