@Override
    public void rollback(final Xid xid) throws XAException {
        try {
            delegate.rollback(xid);
        } catch (final XAException ex) {
            throw mapXAException(ex);
        }
    }
@Test
    void assertRollback() throws XAException {
        singleXAResource.rollback(xid);
        verify(xaResource).rollback(xid);
    }