How to use the typeguard.__init__.ForwardRefPolicy function in typeguard

try:
                    hints = get_type_hints(func, localns=frame_locals)
                except NameError as exc:
                    if forward_refs_policy is ForwardRefPolicy.ERROR:
                        raise

                    typename = str(exc).split("'", 2)[1]
                    for param in signature.parameters.values():
                        if param.annotation == typename:
                            break
                    else:
                        raise

                    func_name = function_name(func)
                    if forward_refs_policy is ForwardRefPolicy.GUESS:
                        if param.name in self.arguments:
                            argtype = self.arguments[param.name].__class__
                            if param.annotation == argtype.__qualname__:
                                func.__annotations__[param.name] = argtype
                                msg = ('Replaced forward declaration {!r} in {} with {!r}'
                                       .format(param.annotation, func_name, argtype))
                                warn(TypeHintWarning(msg))
                                continue

                    msg = 'Could not resolve type hint {!r} on {}: {}'.format(
                        param.annotation, function_name(func), exc)
                    warn(TypeHintWarning(msg))
                    del func.__annotations__[param.name]
                else:
                    break