src/transformers/models/phobert/tokenization_phobert.py/PhobertTokenizer/_tokenize
class PhobertTokenizer:    def _tokenize(self, text):
        """Tokenize a string."""
        split_tokens = []

        words = re.findall(r"\S+\n?", text)

        for token in words:
            split_tokens.extend(list(self.bpe(token).split(" ")))
        return split_tokens