def iextract(self, feat):
        """
        Args:
            feat: tf.Tensor with dim [B, None]

        Returns:
            transcripts: tf.Tensor of dtype tf.string with dim [B]
        """
        # return tf.map_fn(lambda x: tf.numpy_function(self._idx_to_char, [x], tf.string),
        #                  feat, dtype=tf.string)
        tokens=[self.index_to_token[index] for index in feat]
        return tokens

        Args:
            feat: tf.Tensor with dim [B, None]

        Returns:
            transcripts: tf.Tensor of dtype tf.string with dim [B]
        
Inference/PythonInference/utils/text_featurizers.py