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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 unique(flags_class):
 """ A decorator for flags classes to forbid flag aliases. """

    if not is_flags_class_final(flags_class):
        raise TypeError('unique check can be applied only to flags classes that have members')
    if not flags_class.__member_aliases__:
        return flags_class
    aliases = ', '.join('%s -> %s' % (alias, name) for alias, name in flags_class.__member_aliases__.items())
    raise ValueError('duplicate values found in %r: %s' % (flags_class, aliases))