src/transformers/pipelines/feature_extraction.py/FeatureExtractionPipeline/postprocess
class FeatureExtractionPipeline:    def postprocess(self, model_outputs):
        # [0] is the first available tensor, logits or last_hidden_state.
        if self.framework == "pt":
            return model_outputs[0].tolist()
        elif self.framework == "tf":
            return model_outputs[0].numpy().tolist()