code: def eval_in_new(cls, expr, *args, **kwargs):
          
          ctx = cls(*args, **kwargs)
          ctx.env.rec_new(expr)
          return ctx.eval(expr)
docs: :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.