The setting of LoginDomainName attribute of the LoginModuleGBean

[Ivan]

Hi
  In the LoginModuleGBean, there is an attribute named loginDomainName, I
went through the codes, just found that while the WrappingLoginModule is
turned on, those domainNames are used in the Subject as DomainPrincipal.
Except for this, is there any use for those loginDomainNames ? And, I did
not found any example for WrappingLoginModule, so when we would use it ?
 Thanks !
-- 
Ivan