def METHOD_NAME(template_string: str, context=None):
    try:
        config_mapping = etl.config.get_config_map()
        # These assignments are to create backwards-compatibility with old settings files.
        config_mapping.update(
            prefix=config_mapping["object_store.s3.prefix"],
            today=config_mapping["date.today"],
            yesterday=config_mapping["date.yesterday"],
        )
        template = DottedNameTemplate(template_string)
        return template.substitute(config_mapping)
    except (KeyError, ValueError) as exc:
        raise MissingValueTemplateError("failed to render template in {}".format(context)) from exc