}
SortedSet<CommandEntry> sortedFragmentCommandEntries = CommandEntryManager.sortedCommandEntries(fragment.getCommandEntries());
String addedOperationPrefix = fragmentCommandEntry.getOperationPrefix();
String combinedOperationPrefix = operationPrefix == null ? addedOperationPrefix : (operationPrefix + (addedOperationPrefix == null ? "" : addedOperationPrefix));
nestedInteractionList = subInteractionList(req, group, sortedFragmentCommandEntries,isFragment, expandFragments, withinLoop, contactAvailable, combinedOperationPrefix,
indentation, new SortLabelStack(sortLabelStack,sortLabel));
if (nestedInteractionList == null){
if (!interaction.isError()){
interaction.setError(true);
interaction.setErrorDescription(ResourceBundle.getBundle("SmsServices", locale).getString("TooManyNestingLevels"));
}