def METHOD_NAME(self):
    """This method can be used to create the CRLs. If the file can not be created,
    it will be downloaded from the server.
    :return: S_OK(str)/S_ERROR()
    """
    retVal = Utilities.generateRevokedCertsFile()
    if retVal["OK"]:
        return retVal
    # if we can not found the file, we return the directory, where the file should be
    transferClient = self.__getTransferClient()
    casFile = os.path.join(os.path.dirname(retVal["Message"]), "crls.pem")
    with open(casFile, "w") as fd:
        result = transferClient.receiveFile(fd, "CRLs")
        if not result["OK"]:
            return result
        return S_OK(casFile)