src/transformers/pipelines/base.py/PipelineRegistry/register_pipeline
class PipelineRegistry:    def register_pipeline(
        self,
        task: str,
        pipeline_class: type,
        pt_model: Optional[Union[type, Tuple[type]]] = None,
        tf_model: Optional[Union[type, Tuple[type]]] = None,
        default: Optional[Dict] = None,
        type: Optional[str] = None,
    ) -> None:
        if task in self.supported_tasks:
            logger.warning(f"{task} is already registered. Overwriting pipeline for task {task}...")

        if pt_model is None:
            pt_model = ()
        elif not isinstance(pt_model, tuple):
            pt_model = (pt_model,)

        if tf_model is None:
            tf_model = ()
        elif not isinstance(tf_model, tuple):
            tf_model = (tf_model,)

        task_impl = {"impl": pipeline_class, "pt": pt_model, "tf": tf_model}

        if default is not None:
            if "model" not in default and ("pt" in default or "tf" in default):
                default = {"model": default}
            task_impl["default"] = default

        if type is not None:
            task_impl["type"] = type

        self.supported_tasks[task] = task_impl
        pipeline_class._registered_impl = {task: task_impl}