def METHOD_NAME(self, *args):
    form = deepcopy(self)
    name = form.form.__name__
    form.form = lambda *arg: self.form(
        *[arg[k] if args[k] == j else arg[k].zeros()
          for k in range(len(arg) - 1)
          for j in range(int((self.nargs - 1) / (len(arg) - 1)))],
        arg[-1]
    )
    form.form.__name__ = name
    return form