code: public boolean isMember(Principal member)
      {
        if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
          SibTr.entry(tc, "isMember", "is: " + member + ", a member of: " + this);
  
        boolean result = false;
  
        if(member instanceof MPPrincipal)
        {
          List theGroups = ((MPPrincipal)member).getGroups();
          if(theGroups != null)
            result = theGroups.contains(getName());
        }
  
        if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
          SibTr.exit(tc, "isMember", new Boolean(result));
  
        return result;
      }
docs: Returns true if the passed principal is a member of the group.
  This method does a recursive search, so if a principal belongs to a
  group which is a member of this group, true is returned.
  
  @param member the principal whose membership is to be checked.
  
  @return true if the principal is a member of this group,
  false otherwise.