@Override
    public void memberDeparted(DistributionManager distributionManager,
        InternalDistributedMember theId, boolean crashed) {
      signalChange();
    }
Waits until (elder is desiredElder) or (desiredElder is no longer a member) or (the local
member is the elder)

@return true if desiredElder is the elder; false if it is no longer a member or the local
        member is the elder
geode-core/src/main/java/org/apache/geode/distributed/internal/ClusterElderManager.java