code: public boolean deleteGroup(String groupName) {
  		if (groupsFile != null) {
  			lock.writeLock().lock();
  			try {
  				reloadGroupsFromFile();
  				groups.remove(groupName);
  				return writeGroupFile();
  			} finally {
  				lock.writeLock().unlock();
  			}
  		} // end if resourcePath not null
  		return false;
  	}
docs: Deletes the group from the disk
  
  @param groupName
  @return True if successful.