@Test
  public void testExecuteOnKeyOwner() {
    final IExecutorService service = client.getExecutorService(randomString());
    final String mapName = randomString();

    final Member member = instance1.getCluster().getLocalMember();
    final String targetUuid = member.getUuid();
    final String key = generateKeyOwnedBy(instance1);

    service.executeOnKeyOwner(new MapPutRunnable(mapName), key);

    final IMap map = client.getMap(mapName);

    assertTrueEventually(
        new AssertTask() {
          public void run() throws Exception {
            assertTrue(map.containsKey(targetUuid));
          }
        });
  }
 @Test(expected = NullPointerException.class)
 public void testExecuteOnKeyOwner_whenKeyNull() {
   IExecutorService service = client.getExecutorService(randomString());
   service.executeOnKeyOwner(new MapPutRunnable("map"), null);
 }