/// Construct onion packet payloads and keys for sending an onion message along the given
/// `unblinded_path` to the given `destination`.
fn packet_payloads_and_keys<T: CustomOnionMessageContents, S: secp256k1::Signing + secp256k1::Verification>(
secp_ctx: &Secp256k1<S>, unblinded_path: &[PublicKey], destination: Destination,
/// Construct onion packet payloads and keys for sending an onion message along the given
/// `unblinded_path` to the given `destination`.
fn packet_payloads_and_keys<T: CustomOnionMessageContents, S: secp256k1::Signing + secp256k1::Verification>(
secp_ctx: &Secp256k1<S>, unblinded_path: &[PublicKey], destination: Destination,