def close_debt_position(self, symbol, account=None):
        """ Close a debt position and reclaim the collateral

            :param str symbol: Symbol to close debt position for
            :raises ValueError: if symbol has no open call position
        """
        if not account:
            if "default_account" in self.blockchain.config:
                account = self.blockchain.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, full=True, blockchain_instance=self.blockchain)
        debts = self.list_debt_positions(account)
        if symbol not in debts:
            raise ValueError("No call position open for %s" % symbol)
        debt = debts[symbol]
        asset = debt["debt"]["asset"]
        collateral_asset = debt["collateral"]["asset"]
        op = operations.Call_order_update(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "delta_debt": {
                    "amount": int(-float(debt["debt"]) * 10 ** asset["precision"]),
                    "asset_id": asset["id"],
                },
                "delta_collateral": {
                    "amount": int(
                        -float(debt["collateral"]) * 10 ** collateral_asset["precision"]
                    ),
                    "asset_id": collateral_asset["id"],
                },
                "funding_account": account["id"],
                "extensions": [],
            }
        )
        return self.blockchain.finalizeOp(op, account["name"], "active")
Close a debt position and reclaim the collateral

            :param str symbol: Symbol to close debt position for
            :raises ValueError: if symbol has no open call position