materializeMembers() Constructs the List of WorkflowUsers for the given workgroup from it's list of "workgroupMembers" and sets that
as the List of "members" on this Workgroup.
protected void
processRecipientUsers(Recipient recipient, List<WorkflowUser> users, Set<String> userIds, Set<String> workgroupNames) Prevents duplicate users from occuring in the users list as well as preventing infinite loops
should there happen to be cycles in the workgroups.
Constructs the List of WorkflowUsers for the given workgroup from it's list of "workgroupMembers" and sets that
as the List of "members" on this Workgroup.