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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_catalogs(results=30, start=0):
 """ Returns list of all catalogs created on this API key Args: Kwargs: results (int):
 An integer number of results to return start (int):
 An integer starting value for the result set Returns: A list of catalog objects Example: [<catalog - test_artist_catalog>, <catalog - test_song_catalog>, <catalog - my_songs>] """

    result = util.callm("%s/%s" % ('catalog', 'list'), {'results': results, 'start': start})
    cats = [Catalog(**util.fix(d)) for d in result['response']['catalogs']]
    start = result['response']['start']
    total = result['response']['total']
    return ResultList(cats, start, total)