def getDeviceGroupIsIsL3RouterObj(self, deviceGroupObj):
        """ 
        Description
           Get and the Device Group's ISIS L3 Router object.
           Mainly used after configIsIsNgpf().
          
        Parameter
           deviceGroupObj: <str:obj>: /api/v1/sessions/{id}/ixnetwork/topology/{id}/deviceGroup/{1}

        Return
           IsIsL3Router obj: /api/v1/sessions/{id}/ixnetwork/topology/{id}/deviceGroup/{id}/isisL3Router/{id}
        """
        response = self.ixnObj.get(self.ixnObj.httpHeader + deviceGroupObj + '/isisL3Router')
        return response.json()[0]['links'][0]['href']