def d_output(self):
        """Output dimension of model.

        This attribute is required for all SequenceModule instantiations.
        It is used by the rest of the pipeline (e.g. model backbone, decoder) to track the internal shapes of the full model.
        """
        if getattr(self, "_d_output", None) is None:
            raise NotImplementedError("SequenceModule instantiation must specify d_output for decoder")
        return self._d_output
Output dimension of model.

        This attribute is required for all SequenceModule instantiations.
        It is used by the rest of the pipeline (e.g. model backbone, decoder) to track the internal shapes of the full model.
        
analyze/convnexts4nd/src/models/sequence/base.py