def METHOD_NAME(self):
    """Remove any builtins which might have been added by add_builtins, or
    restore overwritten ones to their previous values."""
    remove_builtin = self.remove_builtin
    for key, val in iteritems(self._orig_builtins):
        remove_builtin(key, val)
    self._orig_builtins.clear()
    self._builtins_added = False