src/transformers/models/lxmert/tokenization_lxmert.py/WordpieceTokenizer/__init__
class WordpieceTokenizer:    def __init__(self, vocab, unk_token, max_input_chars_per_word=100):
        self.vocab = vocab
        self.unk_token = unk_token
        self.max_input_chars_per_word = max_input_chars_per_word