(The Stock class) Following the example of the Circle class in Section 9.2, design a class named Stock that contains: ■ A string data field named symbol for the stock’s symbol. ■ A string data field named name for the stock’s name. ■ A double data field named previousClosingPrice that stores the stock price for the previous day. ■ A double data field named currentPrice that stores the stock price for the current time. ■ A constructor that creates a stock with the specified symbol and name. ■ A method named getChangePercent() that returns the percentage changed from previousClosingPrice to currentPrice.