@Override
  public PersistentMemberState getPersistedStateOfMember(PersistentMemberID id) {
    if (isRevoked(id)) {
      return PersistentMemberState.REVOKED;
    }

    // If the peer is marked as equal, indicate they are equal
    if (equalMembers != null && equalMembers.contains(id)) {
      return PersistentMemberState.EQUAL;
    }

    // If we have a member that is marked as online that is an older version of the peers id, tell
    // them they are online
    for (PersistentMemberID onlineMember : persistentMemberView.getOnlineMembers()) {
      if (onlineMember.isOlderOrEqualVersionOf(id)) {
        return PersistentMemberState.ONLINE;
      }
    }

    // If we have a member that is marked as offline that is a newer version of the peers id, tell
    // them they are online
    for (PersistentMemberID offline : persistentMemberView.getOfflineMembers()) {
      if (id.isOlderOrEqualVersionOf(offline)) {
        return PersistentMemberState.OFFLINE;
      }
    }
    return null;
  }
Return what state we have persisted for a given peer's id.
geode-core/src/main/java/org/apache/geode/internal/cache/persistence/PersistenceAdvisorImpl.java