code: def __init__(self, src: str, tgt: str) -> None:
      if MarianMTModel is None:
          raise ValueError("`transformers` is needed for `OPUSBase`")
      super().__init__(f"Helsinki-NLP/opus-mt-{src}-{tgt}")
  
file_path: carefree-learn/cflearn/models/nlp/transformers/opus.py
imports: from typing import Any
  from typing import Optional
  from cftool.types import np_dict_type
  from cftool.types import tensor_dict_type
  from .core import HuggingFaceModel
  from ....types import texts_type
  from ....schema import TrainerState
  from ....constants import PREDICTIONS_KEY
label_desc: Use image node_id 1 to create a new OPUSBase object from inherited base classes: HuggingFaceModel with example: obj = OPUSBase(src, tgt)