def _read_original_file(self, phase):
    "\n        III: format data\n        ---------------------------------------------\n        :param phase:   [str] 'train' or 'test'\n        :return: _rows: [list] of [list] of [str], e.g. [[], ['Inger', 'PER'], ['säger', '0'], ..]\n        "
    file_name = {'train': 'eng.train', 'val': 'eng.testa', 'test': 'eng.testb'}
    file_path_original = join(self.dataset_path, file_name[phase])
    _rows = list()
    if os.path.isfile(file_path_original):
        with open(file_path_original) as f:
            for (i, row) in enumerate(f.readlines()):
                _rows.append(row.strip().split())
        print(f'''
> read {file_path_original}''')
    _rows = [([row[0], row[(- 1)]] if ((len(row) == 4) and (row[0] != '-DOCSTART-')) else list()) for row in _rows]
    return _rows
III: format data
---------------------------------------------
:param phase:   [str] 'train' or 'test'
:return: _rows: [list] of [list] of [str], e.g. [[], ['Inger', 'PER'], ['säger', '0'], ..]
def _read_original_file(self, phase):
    "\n        III: format data\n        ---------------------------------------------\n        :param phase:   [str] 'train' or 'test'\n        :return: _rows: [list] of [list] of [str], e.g. [[], ['Inger', 'PER'], ['säger', '0'], ..]\n        "
    file_name = {'train': 'eng.train', 'val': 'eng.testa', 'test': 'eng.testb'}
    file_path_original = join(self.dataset_path, file_name[phase])
    _rows = list()
    if os.path.isfile(file_path_original):
        with open(file_path_original) as f:
            for (i, row) in enumerate(f.readlines()):
                _rows.append(row.strip().split())
        print(f'
> read {file_path_original}')
    _rows = [([row[0], row[(- 1)]] if ((len(row) == 4) and (row[0] != '-DOCSTART-')) else list()) for row in _rows]
    return _rows