@Override
  public void emergencyClose() {
    view = null;
    if (myChannel != null) {
      if ((services.isShutdownDueToForcedDisconnect() && services.isAutoReconnectEnabled())
          || services.getManager().isReconnectingDS()) {
      } else {
        myChannel.disconnect();
      }
    }
  }
returns the member ID for the given GMSMember object
geode-membership/src/main/java/org/apache/geode/distributed/internal/membership/gms/messenger/JGroupsMessenger.java