Recreate a KrausModel from the dictionary representation.

        :param dict d: The dictionary representing the KrausModel. See `to_dict` for an
            example.
        :return: The deserialized KrausModel.
        :rtype: KrausModel

def from_dict(d):
        """
        Recreate a KrausModel from the dictionary representation.

        :param dict d: The dictionary representing the KrausModel. See `to_dict` for an
            example.
        :return: The deserialized KrausModel.
        :rtype: KrausModel
        """
        kraus_ops = [KrausModel.unpack_kraus_matrix(k) for k in d['kraus_ops']]
        return KrausModel(d['gate'], d['params'], d['targets'], kraus_ops, d['fidelity'])