private function createAddRoleScopeForm(PermissionsGroup $permissionsGroup)
    {
        return $this->createFormBuilder()
                ->setAction($this->generateUrl('admin_permissionsgroup_add_role_scope',
                        array('id' => $permissionsGroup->getId())))
                ->setMethod('PUT')
                ->add('composed_role_scope', 'composed_role_scope')
                ->add('submit', 'submit', array('label' => 'Add permission'))
                ->getForm()
                ;
    }