def METHOD_NAME(modelXbrl, mappedUri, filepath, *args, **kwargs):
    if not (mappedUri.startswith("http://download.companieshouse.gov.uk/") and
            mappedUri.endswith(".zip")):
        return None # not a companies houst zip file
    rssObject = ModelRssObject(modelXbrl, uri=mappedUri, filepath=filepath)
    # find <table> with <a>Download in it
    for instanceFile in modelXbrl.fileSource.dir:
        rssObject.rssItems.append(
            CompaniesHouseItem(modelXbrl, instanceFile, mappedUri + '/' + instanceFile))
    return rssObject