public function can_change_parent($newparentcat) {
        if (!has_capability('moodle/category:manage', $this->get_context())) {
            return false;
        }
        if (is_object($newparentcat)) {
            $newparentcat = self::get($newparentcat->id, IGNORE_MISSING);
        } else {
            $newparentcat = self::get((int)$newparentcat, IGNORE_MISSING);
        }
        if (!$newparentcat) {
            return false;
        }
        if ($newparentcat->id == $this->id || in_array($this->id, $newparentcat->get_parents())) {
            // Can not move to itself or it's own child.
            return false;
        }
        if ($newparentcat->id) {
            return has_capability('moodle/category:manage', context_coursecat::instance($newparentcat->id));
        } else {
            return has_capability('moodle/category:manage', context_system::instance());
        }
    }