src/transformers/models/gpt2/tokenization_gpt2_tf.py/TFGPT2Tokenizer/__init__
class TFGPT2Tokenizer:    def __init__(self, vocab: Dict[str, int], merges: List[str], max_length: int = None, pad_token_id: int = None):
        super().__init__()
        self.pad_token_id = pad_token_id
        self.max_length = max_length
        self.vocab = vocab
        self.merges = merges
        self.tf_tokenizer = BytePairTokenizer(vocab, merges, sequence_length=max_length)