docs: 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;
      }