def get_fp_and_derivation_to_be_used_in_partial_tx(
            self,
            der_suffix: Sequence[int],
            *,
            only_der_suffix: bool,
    ) -> Tuple[bytes, Sequence[int]]:
        """Returns fingerprint and derivation path corresponding to a derivation suffix.
        The fingerprint is either the root fp or the intermediate fp, depending on what is available
        and 'only_der_suffix', and the derivation path is adjusted accordingly.
        """
        pass
Returns fingerprint and derivation path corresponding to a derivation suffix.
        The fingerprint is either the root fp or the intermediate fp, depending on what is available
        and 'only_der_suffix', and the derivation path is adjusted accordingly.
        
electrum/keystore.py