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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(enumeration):
 """Class decorator that ensures only unique members exist in an enumeration."""

    duplicates = []
    for name, member in enumeration.__members__.items():
        if name != member.name:
            duplicates.append((name, member.name))
    if duplicates:
        duplicate_names = ', '.join(
                ["%s -> %s" % (alias, name) for (alias, name) in duplicates]
                )
        raise ValueError('duplicate names found in %r: %s' %
                (enumeration, duplicate_names)
                )
    return enumeration