code: def _new_cls_attr(self, clazz, name, cls=None, mult=MULT_ONE, cont=True,
                        ref=False, bool_assignment=False, position=0):
          
          attr = MetaAttr(name, cls, mult, cont, ref, bool_assignment,
                          position)
          clazz._tx_attrs[name] = attr
          return attr
docs: Creates new meta attribute of this class.