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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 iter_filth_clss():
 """Iterate over all of the filths that are included in this sub-package. This is a convenience method for capturing all new Filth that are added over time. """

    return iter_subclasses(
        os.path.dirname(os.path.abspath(__file__)),
        Filth,
        _is_abstract_filth,
    )