def _find_core_nlu_files_in_directory(directory: Text) -> Tuple[(Set[Text], Set[Text])]:
    story_files = set()
    nlu_data_files = set()
    for (root, _, files) in os.walk(directory, followlinks=True):
        for f in sorted(files):
            full_path = os.path.join(root, f)
            if (not _is_valid_filetype(full_path)):
                continue
            if is_nlu_file(full_path):
                nlu_data_files.add(full_path)
            elif is_story_file(full_path):
                story_files.add(full_path)
    return (story_files, nlu_data_files)
def _find_core_nlu_files_in_directory(directory: Text) -> Tuple[(Set[Text], Set[Text])]:
    story_files = set()
    nlu_data_files = set()
    for (root, _, files) in os.walk(directory, followlinks=True):
        for f in sorted(files):
            full_path = os.path.join(root, f)
            if (not _is_valid_filetype(full_path)):
                continue
            if is_nlu_file(full_path):
                nlu_data_files.add(full_path)
            elif is_story_file(full_path):
                story_files.add(full_path)
    return (story_files, nlu_data_files)