def get_depending_transactions(self, tx_hash: str) -> Set[str]:
        """Returns all (grand-)children of tx_hash in this wallet."""
        with self.lock:
            children = set()
            for n in self.db.get_spent_outpoints(tx_hash):
                other_hash = self.db.get_spent_outpoint(tx_hash, n)
                children.add(other_hash)
                children |= self.get_depending_transactions(other_hash)
            return children
Returns all (grand-)children of tx_hash in this wallet.
electrum/address_synchronizer.py