:meth:`eval` an expression in a new, temporary :class:`Context`.

        This should be safe to use directly on user input.

        Args:
            expr (LispVal): The expression to evaluate.
            *args: Args for the :class:`Context` constructor.
            **kwargs: Kwargs for the :class:`Context` constructor.

def eval_in_new(cls, expr, *args, **kwargs):
        """:meth:`eval` an expression in a new, temporary :class:`Context`.

        This should be safe to use directly on user input.

        Args:
            expr (LispVal): The expression to evaluate.
            *args: Args for the :class:`Context` constructor.
            **kwargs: Kwargs for the :class:`Context` constructor.
        """
        ctx = cls(*args, **kwargs)
        ctx.env.rec_new(expr)
        return ctx.eval(expr)