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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def dict_strict_update(base_dict, update_dict):
 """ This function updates base_dict with update_dict if and only if update_dict does not contain keys that are not already in base_dict. It is essentially a more strict interpretation of the term "updating" the dict. If update_dict contains keys that are not in base_dict, a RuntimeError is raised. :param base_dict: The dict that is to be updated. This dict is modified. :param update_dict: The dict containing the new values. """

    additional_keys = set(update_dict.keys()) - set(base_dict.keys())
    if len(additional_keys) > 0:
        raise RuntimeError(
            'The update dictionary contains keys that are not part of '
            'the base dictionary: {}'.format(str(additional_keys)),
            additional_keys)

    base_dict.update(update_dict)