public class FakeStockQuoteTest {
@Test
public void fakeStockPriceShouldBePlusOrMinusFivePercentOfTheOldPrice() {
FakeStockQuote stockQuote = new FakeStockQuote();
Double origPrice = new Random().nextDouble();
Double newPrice = stockQuote.newPrice(origPrice);
assertThat(newPrice).isGreaterThan(origPrice - (origPrice * 0.05));
assertThat(newPrice).isLessThan(origPrice + (origPrice * 0.05));
}