    def _from_config(cls: Type[_T], config: "PretrainedConfig", **kwargs) -> _T:
        """
        Instantiate this module from a HuggingFace config. Subclasses should override
        this method if you want to be able to instantiate them with `from_pretrained_module()`.
        """
        raise NotImplementedError
Instantiate this module from a HuggingFace config. Subclasses should override
this method if you want to be able to instantiate them with `from_pretrained_module()`.
allennlp/modules/transformer/transformer_module.py