@Test public void recBuffer05()
{

    RecordBuffer rb = make(4,5) ;
    contains(rb, 2, 4, 6, 8) ;
    rb.shiftUp(2) ;
    rb.set(2, r(0)) ;
    contains(rb, 2, 4, 0, 6, 8) ;
    rb.shiftDown(2) ;
    contains(rb, 2, 4, 6, 8) ;
}