code: @Override
      String[] get_device_name_list(final boolean fwd) {
  	synchronized (this) {
  	    int i = 0;
  	    final String[] dl = new String[get_size_i(fwd)];
  	    final Iterator it = elements.iterator();
  	    while (it.hasNext()) {
  		final GroupElement e = (GroupElement) it.next();
  		if (e instanceof GroupDeviceElement || fwd) {
  		    final String[] sub_dl = e.get_device_name_list(fwd);
  		    for (int j = 0; j < sub_dl.length; j++, i++) {
  			dl[i] = sub_dl[j];
  		    }
  		}
  	    }
  	    return dl;
  	}
      }
docs: Returns the group's device list - access limited to package Group