def check_input(self, port_name):
        if not self.has_input(port_name):
            raise ModuleError(self, "'%s' is a mandatory port" % port_name)
Respond to /server/state.
dataset/ETHPy150Open VisTrails/VisTrails/vistrails/core/modules/vistrails_module.py/Module.check_input--crossover with--dataset/ETHPy150Open google/grr/grr/server/data_server/data_server.py/DataServerHandler.HandleState