public void test_lower() throws Exception {
NavigableMap map = tm.subMap(objArray[102].toString(), true,
objArray[103].toString(), false);
assertEquals(objArray[102].toString(), map.higherKey(objArray[101]
.toString()));
assertEquals(null, map.higherKey(objArray[102].toString()));
assertEquals(null, map.higherKey(objArray[103].toString()));
assertEquals(null, map.higherKey(objArray[104].toString()));
assertEquals(objArray[102].toString(), map.ceilingKey(objArray[101]
.toString()));
assertEquals(objArray[102].toString(), map.ceilingKey(objArray[102]