module foo {
    namespace foo;
    prefix foo;

    import ietf-restconf {
        prefix rc;
        revision-date 2017-01-26;
    }

    revision 2017-06-01;

    rc:yang-data "my-yang-data" {
        // two top level containers, but only one is allowed = should throw an exception
        container cont-1 {}
        uses grp-1;
    }

    grouping grp-1 {
        uses grp-2;
    }

    grouping grp-2 {
        container cont-2 {}
    }
}