src/transformers/models/layoutlmv2/tokenization_layoutlmv2.py/LayoutLMv2Tokenizer/_convert_id_to_token
class LayoutLMv2Tokenizer:    def _convert_id_to_token(self, index):
        """Converts an index (integer) in a token (str) using the vocab."""
        return self.ids_to_tokens.get(index, self.unk_token)