def _load_data_from_txt(self, filepath):
        """load data from CUB txt file, the every line of the file is idx and a
        data item."""
        pairs = list_from_file(filepath)
        data_dict = dict()
        for pair in pairs:
            idx, data_item = pair.split()
            # all the index starts from 1 in CUB files,
            # here we need to '- 1' to let them start from 0.
            data_dict[int(idx) - 1] = data_item
        return data_dict
load data from CUB txt file, the every line of the file is idx and a
        data item.
mmpretrain/datasets/cub.py