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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 filename_match(filename):
 """ Check if options.filename contains a pattern that matches filename. If options.filename is unspecified, this always returns True. """

    if not options.filename:
        return True
    for pattern in options.filename:
        if fnmatch(filename, pattern):
            return True