docs: 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)