code: def GetBalance(self, asset_id, watch_only=0):
          
          total = Fixed8(0)
  
          if type(asset_id) is NEP5Token.NEP5Token:
              return self.GetTokenBalance(asset_id, watch_only)
  
          for coin in self.GetCoins():
              if coin.Output.AssetId == asset_id:
                  if coin.State & CoinState.Confirmed > 0 and \
                          coin.State & CoinState.Spent == 0 and \
                          coin.State & CoinState.Locked == 0 and \
                          coin.State & CoinState.Frozen == 0 and \
                          coin.State & CoinState.WatchOnly == watch_only:
                      total = total + coin.Output.Value
  
          return total
docs: Get the balance of a specific token by its asset id.
  
          Args:
              asset_id (NEP5Token|TransactionOutput): an instance of type neo.Wallets.NEP5Token or neo.Core.TX.Transaction.TransactionOutput to get the balance from.
              watch_only (bool): True, to limit to watch only wallets.
  
          Returns:
              Fixed8: total balance.