@Test public void recBuffer07()
{

    RecordBuffer rb = make(4,5) ;
    contains(rb, 2, 4, 6, 8) ;
    rb.shiftUp(3) ;
    rb.set(3, r(1)) ;
    contains(rb, 2, 4, 6, 1, 8) ;
    rb.shiftDown(3) ;
    contains(rb, 2, 4, 6, 8) ;
}