### Question:
SingleMarketDataBox implements ImmutableBean, MarketDataBox<T>, Serializable { @Override public Stream<T> stream() { return Stream.of(value); } private  SingleMarketDataBox(
      T value); static SingleMarketDataBox<T> of(T value); @Override T getSingleValue(); @Override ScenarioArray<T> getScenarioValue(); @Override T getValue(int scenarioIndex); @Override boolean isSingleValue(); @Override int getScenarioCount(); @Override Class<?> getMarketDataType(); @Override MarketDataBox<R> map(Function<T, R> fn); @Override MarketDataBox<R> mapWithIndex(int scenarioCount, ObjIntFunction<T, R> fn); @Override MarketDataBox<R> combineWith(MarketDataBox<U> other, BiFunction<T, U, R> fn); @Override Stream<T> stream(); @SuppressWarnings("rawtypes") static SingleMarketDataBox.Meta meta(); @SuppressWarnings("unchecked") static SingleMarketDataBox.Meta<R> metaSingleMarketDataBox(Class<R> cls); @SuppressWarnings("unchecked") @Override SingleMarketDataBox.Meta<T> metaBean(); T getValue(); @Override boolean equals(Object obj); @Override int hashCode(); @Override String toString();  }### Answer:
@Test public void stream() { MarketDataBox<Integer> box = MarketDataBox.ofSingleValue(27); List<Integer> list = box.stream().collect(toList()); assertThat(list).isEqualTo(ImmutableList.of(27)); }