/// Construct the invoice's HRP and signatureless data into a preimage to be hashed.
pub fn construct_invoice_preimage(hrp_bytes: &[u8], data_without_signature: &[u5]) -> Vec<u8> {
/// Construct the invoice's HRP and signatureless data into a preimage to be hashed.
pub fn construct_invoice_preimage(hrp_bytes: &[u8], data_without_signature: &[u5]) -> Vec<u8> {