def _get_payment_key(self, payment_hash: bytes) -> bytes:
        """Return payment bucket key.
        We bucket htlcs based on payment_hash+payment_secret. payment_secret is included
        as it changes over a trampoline path (in the outer onion), and these paths can overlap.
        """
        payment_secret = self.get_payment_secret(payment_hash)
        return payment_hash + payment_secret
Return payment bucket key.
        We bucket htlcs based on payment_hash+payment_secret. payment_secret is included
        as it changes over a trampoline path (in the outer onion), and these paths can overlap.
        
electrum/lnworker.py