code: def _test_get_spot_value_live(self):
      # asset_finder = self.data_portal_live.asset_finder
  
      # assets = [
      #     asset_finder.lookup_symbol('eth_btc', self.bitfinex),
      #     asset_finder.lookup_symbol('eth_btc', self.bittrex)
      # ]
      # now = pd.Timestamp.utcnow()
      # value = self.data_portal_live.get_spot_value(
      #     assets, 'price', now, '1m')
      pass
  
file_path: catalyst/tests/exchange/test_data_portal.py
imports: import pandas
  from logbook import Logger
  from catalyst import get_calendar
  from catalyst.exchange.exchange_asset_finder import ExchangeAssetFinder
  from catalyst.exchange.exchange_data_portal import DataPortalExchangeBacktest, DataPortalExchangeLive
  from catalyst.exchange.utils.factory import get_exchanges
label_desc: Use image node_id 3 for calling the TestExchangeDataPortal obj's underlying member method code with example usage: obj._test_get_spot_value_live() without return types