[Twisted-Python] Multiple Cred Checkers and Avatar Types

[Andy Gayton]

Hey all,

Is it possible to tie the type of avatar a realm returns to the cred 
checker which successfully authenticated the user?  For example, if the 
user requesting a IConchUser interface authenticates against the unix 
password file the realm would know to return a UnixConchUser - if the 
authenticated against a smbpasswordish like file they realm would return 
a SmbishConchUser.

Is this not the right way to be thinking of cred?

Any advice is greatly appreciated,
Andy.