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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 slugify(text, sep='-'):
 """A simple slug generator."""

    text = stringify(text)
    if text is None:
        return None
    text = text.replace(sep, WS)
    text = normalize(text, ascii=True)
    if text is None:
        return None
    return text.replace(WS, sep)