code: def balance(self, symbol):
          
          if isinstance(symbol, dict) and "symbol" in symbol:
              symbol = symbol["symbol"]
          balances = self.balances
          for b in balances:
              if b["symbol"] == symbol:
                  return b
          return self.amount_class(0, symbol, blockchain_instance=self.blockchain)
docs: Obtain the balance of a specific Asset. This call returns instances of
              :class:`amount.Amount`.