@Override
    public void memberSuspect(DistributionManager distributionManager, InternalDistributedMember id,
        InternalDistributedMember whoSuspected, String reason) {
      suspectReasons.add(reason);
    }
New test hook which blocks before closing channel.
geode-core/src/distributedTest/java/org/apache/geode/distributed/LocatorDUnitTest.java