@Override
  public GMSQuorumChecker<ID> getQuorumChecker() {
    GMSMembershipView<ID> view = this.view;
    if (view == null) {
      view = services.getJoinLeave().getView();
      if (view == null) {
        view = services.getJoinLeave().getPreviousView();
        if (view == null) {
          return null;
        }
      }
    }
    GMSQuorumChecker<ID> qc =
        new GMSQuorumChecker<>(view, services.getConfig().getLossThreshold(), myChannel,
            encrypt);
    qc.initialize();
    return qc;
  }
returns the member ID for the given GMSMember object
geode-membership/src/main/java/org/apache/geode/distributed/internal/membership/gms/messenger/JGroupsMessenger.java