code: def list_debt_positions(self, 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)
  
          r = {}
          for debt in account.get("call_orders"):
              base = Asset(
                  debt["call_price"]["base"]["asset_id"],
                  full=True,
                  blockchain_instance=self.blockchain,
              )
              quote = Asset(
                  debt["call_price"]["quote"]["asset_id"],
                  full=True,
                  blockchain_instance=self.blockchain,
              )
              if not quote.is_bitasset:
                  continue
              quote.ensure_full()
              bitasset = quote["bitasset_data"]
              settlement_price = Price(
                  bitasset["current_feed"]["settlement_price"],
                  blockchain_instance=self.blockchain,
              )
              if not settlement_price:
                  continue
              call_price = Price(debt["call_price"], blockchain_instance=self.blockchain)
              collateral_amount = Amount({"amount": debt["collateral"], "asset": base})
              debt_amount = Amount({"amount": debt["debt"], "asset": quote})
              r[quote["symbol"]] = {
                  "collateral": collateral_amount,
                  "debt": debt_amount,
                  "call_price": call_price,
                  "settlement_price": settlement_price,
                  "ratio": float(collateral_amount)
                  / float(debt_amount)
                  * float(settlement_price),
              }
          return r
docs: List Call Positions (borrowed assets and amounts)
  
              :return: Struct of assets with amounts and call price
              :rtype: dict
  
              **Example**:
  
              .. code-block: js
  
                  {'USD': {'collateral': '865893.75000',
                           'collateral_asset': 'BTS',
                           'debt': 120.00000}