@Test
  public void removeOlderMembersWithEqualTimeStampsInDifferentDiskStores() {
    long timeStamp = 239874; // anything
    // all diskStoreIDs in set are different so nothing to remove
    Set<PersistentMemberID> aSet = new HashSet<>();
    aSet.add(createPersistentMemberID(getNewDiskStoreID(), timeStamp));
    aSet.add(createPersistentMemberID(getNewDiskStoreID(), timeStamp));
    aSet.add(createPersistentMemberID(getNewDiskStoreID(), timeStamp));
    aSet.add(createPersistentMemberID(getNewDiskStoreID(), timeStamp));

    persistenceAdvisorImpl.removeOlderMembers(aSet);

    assertThat(aSet).hasSize(4);
  }
GEODE-5402: This test creates a scenario where a member has two versions (based on timeStamp)
of another member. The call to getMembersToWaitFor should return that we wait for neither of
them.
geode-core/src/test/java/org/apache/geode/internal/cache/persistence/PersistenceAdvisorImplTest.java