def METHOD_NAME(
    self,
    private_key: PrivateKey,
    chain_id: int = None,  # unused until SpuriousDragon
) -> FrontierTransaction:
    v, r, s = create_transaction_signature(self, private_key)
    return FrontierTransaction(
        nonce=self.nonce,
        gas_price=self.gas_price,
        gas=self.gas,
        to=self.to,
        value=self.value,
        data=self.data,
        v=v,
        r=r,
        s=s,
    )