public static void disableDisconnectOnQuorumLossForTesting(DistributedSystem msys) {
    msys.getLogWriter().info("crashing distributed system: " + msys);
    Distribution mgr = getDistribution(msys);
    ((GMSMembership) mgr.getMembership()).disableDisconnectOnQuorumLossForTesting();
  }
wait for a member to leave the view. Throws an assertionerror if the timeout period elapses
before the member leaves
geode-dunit/src/main/java/org/apache/geode/distributed/internal/membership/api/MembershipManagerHelper.java