@Override
  public boolean tryToLockWebLeader() {
    IAtomicReference<UUID> leader = hzMember.getAtomicReference(LEADER);
    return leader.compareAndSet(null, hzMember.getUuid());
  }
@Test
  public void tryToLockWebLeader_returns_true_only_for_the_first_call() {
    try (ClusterAppStateImpl underTest = new ClusterAppStateImpl(new TestAppSettings(), newHzMember(),
      mock(EsConnector.class), mock(AppNodesClusterHostsConsistency.class))) {
      assertThat(underTest.tryToLockWebLeader()).isTrue();
      assertThat(underTest.tryToLockWebLeader()).isFalse();
    }
  }