@Test public void test_next_dir_infinity(){

    BTreeMap m = new BTreeMap(engine,32,true,false, null,null,null,null);
    BTreeMap.DirNode d = new BTreeMap.DirNode(
            new Object[]{null,62,68, 71},
            new long[]{10,20,30,40});
    assertEquals(10, m.nextDir(d, 33));
    assertEquals(10, m.nextDir(d, 62));
    assertEquals(20, m.nextDir(d, 63));
    d = new BTreeMap.DirNode(
            new Object[]{44,62,68, null},
            new long[]{10,20,30,40});
    assertEquals(10, m.nextDir(d, 62));
    assertEquals(10, m.nextDir(d, 44));
    assertEquals(10, m.nextDir(d, 48));
    assertEquals(20, m.nextDir(d, 63));
    assertEquals(20, m.nextDir(d, 64));
    assertEquals(20, m.nextDir(d, 68));
    assertEquals(30, m.nextDir(d, 69));
    assertEquals(30, m.nextDir(d, 70));
    assertEquals(30, m.nextDir(d, 71));
    assertEquals(30, m.nextDir(d, 72));
    assertEquals(30, m.nextDir(d, 73));
}