static PropertySequence getPropertySequence(Node nMembers, UserManagerImpl userManager) throws RepositoryException {
Comparator<String> order = Rank.comparableComparator();
int maxChildren = userManager.getGroupMembershipSplitSize();
int minChildren = maxChildren / 2;
TreeManager treeManager = new BTreeManager(nMembers, minChildren, maxChildren, order,
userManager.isAutoSave());
return ItemSequence.createPropertySequence(treeManager);
}