Overwrite existing definitions w.r.t 'atom' with a dummy definition instance. A dummy definition will not be
        removed during simplification.

        :param Atom atom:
        :param CodeLocation code_loc:
        :param object data:
        :return: None

def kill_definitions(self, atom, code_loc, data=None, dummy=True):
        """
        Overwrite existing definitions w.r.t 'atom' with a dummy definition instance. A dummy definition will not be
        removed during simplification.

        :param Atom atom:
        :param CodeLocation code_loc:
        :param object data:
        :return: None
        """

        if data is None:
            data = DataSet(Undefined(atom.size), atom.size)

        self.kill_and_add_definition(atom, code_loc, data, dummy=dummy)