@Override
  public void memberLeft(MembershipEvent event) {}
Invoked when a member has gracefully left the distributed system. Also invoked when a client
has gracefully disconnected from this process. or when this process has gracefully disconnected
from a <code>CacheServer</code>.
geode-core/src/main/java/org/apache/geode/management/membership/UniversalMembershipListenerAdapter.java