Access the external group id - role name map for this user in all external groups.
If you can do some type of directory lookup to find out some
Attribute of this user you could conditionally auto-add them
to any number of these "virtual groups"
You might try sakai.students, sakai.faculty,
There is nothing specific about the string "sakai." these could
easily be something like course.eecs280, shib:yale.edu:faculty,
One caveat - this class is respnsbile for handling the unpacking
when an admin wants to put in multiple external providers
The code below uses the common convention of using "+" (homage
to "or") to concatenate IDs. So the user above us could set the
provider ID in the Sakai Realms Tool to be
to indicate thatr membership in either group is OK.
To indicate membership in multiple groups in *this routine* add
additional entries in the hash map (i.e. do not use the + notation
in this routine).