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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 list_styles(style_name):
 """ Just list all different styles entries """

    style = get_style_by_name(style_name)

    keys = list(style)[0][1]
    Styles = namedtuple("Style", keys)

    existing_styles = {}

    for ttype, ndef in style:
        s = Styles(**ndef)
        if s in existing_styles:
            existing_styles[s].append(ttype)
        else:
            existing_styles[s] = [ttype]

    for ndef, ttypes in existing_styles.items():
        print(ndef)
        for ttype in sorted(ttypes):
            print("\t%s" % str(ttype).split("Token.",1)[1])