def METHOD_NAME(self):
    # Get default aliases config filenames:
    #   all files from ALIASES_DROPIN_DIR,
    #   and ALIASES_USER_PATH as the last one (-> override all others)
    ignored_filenames = [os.path.basename(ALIASES_CONF_PATH),
                         os.path.basename(ALIASES_USER_PATH)]
    def _ignore_filename(filename):
        return filename in ignored_filenames or\
            filename.startswith('.') or\
            not filename.endswith(('.conf', '.CONF'))
    filenames = []
    try:
        if not os.path.exists(ALIASES_DROPIN_DIR):
            os.mkdir(ALIASES_DROPIN_DIR)
        for fn in sorted(os.listdir(ALIASES_DROPIN_DIR)):
            if _ignore_filename(fn):
                continue
            filenames.append(os.path.join(ALIASES_DROPIN_DIR, fn))
    except (IOError, OSError) as e:
        raise dnf.exceptions.ConfigError(e)
    if os.path.exists(ALIASES_USER_PATH):
        filenames.append(ALIASES_USER_PATH)
    return filenames