g loss becomes zero or negative
        # to address bug in keras_contrib code for CRF.
        # We restore the weights from previous best epoch
        # rather than this epoch.
        crf = U.is_crf(self.model)
        if crf:
            current_loss = logs.get(&#34;loss&#34;)
            current_val_loss = logs.get(&#34;val_loss&#34;, None)
            if (current_loss is not None and current_loss &lt;= 0.0) or (
                current_val_loss is not None and current_val_loss &lt;= 0.0
            )