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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 dump_with_fn(dump_fn, data, stream, **options):
 """ Dump 'data' to a string if 'stream' is None, or dump 'data' to a file or file-like object 'stream'. :param dump_fn: Callable to dump data :param data: Data to dump :param stream: File or file like object or None :param options: optional keyword parameters :return: String represents data if stream is None or None """

    if stream is None:
        return dump_fn(data, **options)

    return dump_fn(data, stream, **options)