code: def close_debt_position(self, symbol, account=None):
          
          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")
docs: 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