def _check_params(self,params):
        """
        Print a warning if params contains something that is not a
        Parameter of the overridden object.
        """
        overridden_object_params = list(self._overridden.param)
        for item in params:
            if item not in overridden_object_params:
                self.param.warning("'%s' will be ignored (not a Parameter).",item)
Print a warning if params contains something that is not a
        Parameter of the overridden object.