protected function insertRoles(array $roles)
    {
        foreach ($roles as $role) {
            if (null === $role->getParent()) {
                $this->addRole($role);
            } else {
                $parents   = [];
                $parents[] = $role->getParent()->getRoleId();
                $this->addRole($role, $parents);
            }
        }

        return $this;
    }