def METHOD_NAME(cfg):
    """Force the dataset to be dumped in lmdb format.
    Args:
        cfg (Config): Config object.
    Returns:
        Config: Config object.
    """
    for split in ['train', 'val', 'test']:
        preparer_cfg = cfg.get(f'{split}_preparer')
        if preparer_cfg:
            if preparer_cfg.get('dumper') is None:
                raise ValueError(
                    f'{split} split does not come with a dumper, '
                    'so most likely the annotations are MMOCR-ready and do '
                    'not need any adaptation, and it '
                    'cannot be dumped in LMDB format.')
            preparer_cfg.dumper['type'] = 'TextRecogLMDBDumper'
    cfg.config_generator['dataset_name'] = f'{cfg.dataset_name}_lmdb'
    for split in ['train_anns', 'val_anns', 'test_anns']:
        if split in cfg.config_generator:
            # It can be None when users want to clear out the default
            # value
            if not cfg.config_generator[split]:
                continue
            ann_list = cfg.config_generator[split]
            for ann_dict in ann_list:
                ann_dict['ann_file'] = (
                    osp.splitext(ann_dict['ann_file'])[0] + '.lmdb')
        else:
            if split == 'train_anns':
                ann_list = [dict(ann_file='textrecog_train.lmdb')]
            elif split == 'test_anns':
                ann_list = [dict(ann_file='textrecog_test.lmdb')]
            else:
                ann_list = []
        cfg.config_generator[split] = ann_list
    return cfg