    def forward_torchscript(self, net_input: Dict[str, Tensor]):
        """A TorchScript-compatible version of forward.

        Encoders which use additional arguments may want to override
        this method for TorchScript compatibility.
        """
        if torch.jit.is_scripting():
            return self.forward(
                src_tokens=net_input["src_tokens"],
                src_lengths=net_input["src_lengths"],
            )
        else:
            return self.forward_non_torchscript(net_input)
A TorchScript-compatible version of forward.

Encoders which use additional arguments may want to override
this method for TorchScript compatibility.
fairseq/models/fairseq_encoder.py