### Question:
RandomGeneratorImpl implements RandomGenerator { @Override public List<Double> randDoubles(int size, double lowBound, double upBound) { List<Double> list = new ArrayList<>(); DoubleStream stream = rand.doubles(size, lowBound, upBound); stream.forEach(list::add); return list; }  @Override char randLowerCaseChar(); @Override char randUpperCaseChar(); @Override char randChar(); @Override List<Character> randLowerCaseChars(int num); @Override List<Character> randUpperCaseChars(int num); @Override List<Character> randChars(int num); @Override int randInt(int lowBound, int upBound); @Override List<Integer> randIntegers(int lowBount, int upBount, int length); @Override String randString(int charCount, int intCount, boolean mustSeartWithAlph); @Override List<String> randStrings(int size, int alphNum, int digitNum, boolean mustStartWithAlph); @Override double randDouble(double lowBound, double upBound); @Override List<Double> randDoubles(int size, double lowBound, double upBound); @Override boolean randBoolean();  }### Answer:
@Test public void randDoubles() { int size = 1000; int low = 0; int high = 10; List<Double> list = randomGenerator.randDoubles(size, low, high); list.forEach(d -> assertTrue(d >= low && d < high)); }