/** putIfAbsent(null, x) throws NPE */
public void testPutIfAbsent1_NullPointerException() {
try {
ConcurrentNavigableMap c = map5();
c.putIfAbsent(null, "whatever");
shouldThrow();
} catch (NullPointerException success) {
}
}
/** putIfAbsent does not add the pair if the key is already present */
public void testDescendingPutIfAbsent2() {
ConcurrentNavigableMap map = dmap5();
assertEquals("A", map.putIfAbsent(m1, "Z"));
}
/** putIfAbsent works when the given key is not present */
public void testDescendingPutIfAbsent() {
ConcurrentNavigableMap map = dmap5();
map.putIfAbsent(six, "Z");
assertTrue(map.containsKey(six));
}
/** putIfAbsent does not add the pair if the key is already present */
public void testPutIfAbsent2() {
ConcurrentNavigableMap map = map5();
assertEquals("A", map.putIfAbsent(one, "Z"));
}