def previous_label_token_log_proba(self) -> tf.Tensor:
        """Calculates the probability to predict token that preceded to label token.

        Returns:    tf.Tensor,  shape = [batch_size, max_logit_length, max_label_length + 1]
        """
        previous_label_token_log_proba = tf.gather(
            params=self.logproba,
            indices=self.preceded_label,
            axis=2,
            batch_dims=1,
        )
        # shape = [batch_size, max_logit_length, max_label_length + 1]
        return previous_label_token_log_proba
Calculates the probability to predict token that preceded to label token.

        Returns:    tf.Tensor,  shape = [batch_size, max_logit_length, max_label_length + 1]
        
tensorflow_asr/losses/impl/ctc_tpu.py