@Test public void compile1()
{

    int[] x = ColumnMap.compileMapping("SPO", "POS") ;
    // SPO -> POS so col 0 goes to col 2, col 1 goes to col 0 and col 2 goes to col 1
    int[] expected = { 2,0,1 } ;
    assertArrayEquals(expected, x) ;
}