src/transformers/models/bertweet/tokenization_bertweet.py/BertweetTokenizer/normalizeToken
class BertweetTokenizer:    def normalizeToken(self, token):
        """
        Normalize tokens in a Tweet
        """
        lowercased_token = token.lower()
        if token.startswith("@"):
            return "@USER"
        elif lowercased_token.startswith("http") or lowercased_token.startswith("www"):
            return "HTTPURL"
        elif len(token) == 1:
            if token in self.special_puncts:
                return self.special_puncts[token]
            if self.demojizer is not None:
                return self.demojizer(token)
            else:
                return token
        else:
            return token