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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 cls_sets(cls, wanted_cls, registered=True):
 """ Return a list of all `wanted_cls` attributes in this class, where `wanted_cls` is the desired attribute type. """

    sets = []
    for attr in dir(cls):
        if attr.startswith('_'):
            continue
        val = getattr(cls, attr, None)
        if not isinstance(val, wanted_cls):
            continue
        if (not registered) and getattr(val, '_registered', False):
            continue
        sets.append(val)
    return sets