src/transformers/models/gpt_neo/configuration_gpt_neo.py/GPTNeoOnnxConfig/outputs
class GPTNeoOnnxConfig:    def outputs(self) -> Mapping[str, Mapping[int, str]]:
        common_outputs = super().outputs
        if self.use_past:
            for i in range(self._config.num_layers):
                common_outputs[f"present.{i}.key"] = {0: "batch", 2: "past_sequence + sequence"}
                common_outputs[f"present.{i}.value"] = {0: "batch", 2: "past_sequence + sequence"}

            return common_outputs

        return common_outputs