($source: expr, $middle: expr, $dest: expr) => { {
let payment_hash = Sha256::hash(&[payment_id; 1]);
payment_id = payment_id.wrapping_add(1);
($source: expr, $middle: expr, $dest: expr) => { {
let payment_hash = Sha256::hash(&[payment_id; 1]);
payment_id = payment_id.wrapping_add(1);