@Override
    protected void handleEvent(ClusterDistributionManager manager, MembershipListener listener) {
      listener.quorumLost(manager, getFailures(), getRemaining());
    }
This is an event reflecting that a InternalDistributedMember may be missing but has not yet
left the system.
geode-core/src/main/java/org/apache/geode/distributed/internal/ClusterDistributionManager.java