code: def add(assetclass: int, symbol: str):
      
      assert isinstance(symbol, str)
      assert isinstance(assetclass, int)
  
      symbol = symbol.upper()
      app = AppAggregate()
      new_item = app.add_stock_to_class(assetclass, symbol)
      print(f"Record added: {new_item}.")
docs: Add a stock to an asset class