public void initialize() {
    receivedAcks = ConcurrentHashMap.newKeySet();

    pingPonger = new GMSPingPonger();
    myAddress = (JGAddress) channel.down(new Event(Event.GET_LOCAL_ADDRESS));

    addressConversionMap = new ConcurrentHashMap<>(lastView.size());
    List<ID> members = lastView.getMembers();
    for (ID addr : members) {
      SocketAddress sockaddr =
          new InetSocketAddress(addr.getInetAddress(), addr.getMembershipPort());
      addressConversionMap.put(sockaddr, addr);
    }

    isInfoEnabled = logger.isInfoEnabled();
    resume();
  }
GMSQuorumChecker is the implementation of QuorumChecker and can be used to determine
whether a quorum of membership is accessible.
geode-membership/src/main/java/org/apache/geode/distributed/internal/membership/gms/messenger/GMSQuorumChecker.java