def get_bias(self) -> Union[None, Dict[str, tf.Variable]]:
        """
        Dict of bias attached to an LM head. The key represents the name of the bias attribute.

        Return:
            `tf.Variable`: The weights representing the bias, None if not an LM model.
        """
        if self.get_lm_head() is not None:
            lm_head = self.get_lm_head()
            try:
                return lm_head.get_bias()
            except AttributeError:
                self.build()

                return lm_head.get_bias()
        return None

        Dict of bias attached to an LM head. The key represents the name of the bias attribute.

        Return:
            `tf.Variable`: The weights representing the bias, None if not an LM model.
        
dpkd/transformers/src/transformers/modeling_tf_utils.py