def METHOD_NAME() -> List[str]:
    """
    Return a list of valid architectures found in the import signatures
    :return: All architectures which are known to Cobbler according to the signature cache.
    """
    archs: List[str] = []
    try:
        for breed in get_valid_breeds():
            for operating_system in list(signature_cache["breeds"][breed].keys()):
                archs += signature_cache["breeds"][breed][operating_system][
                    "supported_arches"
                ]
    except Exception:
        pass
    return utils.uniquify(archs)