if (usernames.isEmpty() || groupName == null || groupName.length()==0) {
usersForContentType = usernames;
} else {
usersForContentType = new ArrayList<String>();
IApsAuthorityManager groupManager = (IApsAuthorityManager) super.getBeanFactory().getBean(SystemConstants.GROUP_MANAGER);
IApsAuthority authority = groupManager.getAuthority(groupName);
List<String> usersWithAuth = groupManager.getUsernamesByAuthority(authority);
for (int i = 0; i < usernames.size(); i++) {
String username = usernames.get(i);
if (null == username) {
continue;