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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 _whatsnd(data):
 """Try to identify a sound file type. sndhdr.what() has a pretty cruddy interface, unfortunately. This is why we re-do it here. It would be easier to reverse engineer the Unix 'file' command and use the standard 'magic' file, as shipped with a modern Unix. """

    hdr = data[:512]
    fakefile = BytesIO(hdr)
    for testfn in sndhdr.tests:
        res = testfn(hdr, fakefile)
        if res is not None:
            return _sndhdr_MIMEmap.get(res[0])
    return None