public double getDividendYield(SimpleStock ss) {
   double dividendYield;
   if (ss.getType().equals("Common")) {
     dividendYield = ss.getLastDividend() / getPrice(ss);
   } else {
     dividendYield = (ss.getFixedDividend() * ss.getParValue()) / getPrice(ss);
   }
   return dividendYield;
 }
 public void addTrade(SimpleStock ss, int quantity, String indicator, double price) {
   Trade trade = new Trade(DateTime.now(), quantity, indicator, price);
   if (stockTrades.get(ss.getStockSymbol()).size() > 0) {
     stockTrades.get(ss.getStockSymbol()).add(trade);
   } else {
     List<Trade> trades = new ArrayList<Trade>();
     trades.add(trade);
     stockTrades.put(ss.getStockSymbol(), trades);
   }
 }
  public double getPrice(SimpleStock ss) {
    List<Trade> listTrades = stockTrades.get(ss.getStockSymbol());
    for (Trade tr : listTrades) {}

    return 0;
  }
 public void addSimpleStock(SimpleStock ss) {
   simpleStockCollection.put(ss.getStockSymbol(), ss);
 }