### Question:
DoubleArray implements Matrix, ImmutableBean, Serializable { public static DoubleArray filled(int size) { if (size == 0) { return EMPTY; } return new DoubleArray(new double[size]); } private  DoubleArray(double[] array); static DoubleArray of(); static DoubleArray of(double value); static DoubleArray of(double value1, double value2); static DoubleArray of(double value1, double value2, double value3); static DoubleArray of(double value1, double value2, double value3, double value4); static DoubleArray of(
      double value1,
      double value2,
      double value3,
      double value4,
      double value5); static DoubleArray of(
      double value1,
      double value2,
      double value3,
      double value4,
      double value5,
      double value6); static DoubleArray of(
      double value1,
      double value2,
      double value3,
      double value4,
      double value5,
      double value6,
      double value7); static DoubleArray of(
      double value1,
      double value2,
      double value3,
      double value4,
      double value5,
      double value6,
      double value7,
      double value8); static DoubleArray of(
      double value1,
      double value2,
      double value3,
      double value4,
      double value5,
      double value6,
      double value7,
      double value8,
      double... otherValues); static DoubleArray of(int size, IntToDoubleFunction valueFunction); static DoubleArray of(DoubleStream stream); static DoubleArray ofUnsafe(double[] array); static DoubleArray copyOf(Collection<Double> collection); static DoubleArray copyOf(double[] array); static DoubleArray copyOf(double[] array, int fromIndex); static DoubleArray copyOf(double[] array, int fromIndexInclusive, int toIndexExclusive); static DoubleArray filled(int size); static DoubleArray filled(int size, double value); @Override int dimensions(); @Override int size(); boolean isEmpty(); double get(int index); boolean contains(double value); int indexOf(double value); int lastIndexOf(double value); void copyInto(double[] destination, int offset); DoubleArray subArray(int fromIndexInclusive); DoubleArray subArray(int fromIndexInclusive, int toIndexExclusive); double[] toArray(); double[] toArrayUnsafe(); List<Double> toList(); DoubleStream stream(); void forEach(IntDoubleConsumer action); DoubleArray with(int index, double newValue); DoubleArray plus(double amount); DoubleArray minus(double amount); DoubleArray multipliedBy(double factor); DoubleArray dividedBy(double divisor); DoubleArray map(DoubleUnaryOperator operator); DoubleArray mapWithIndex(IntDoubleToDoubleFunction function); DoubleArray plus(DoubleArray other); DoubleArray minus(DoubleArray other); DoubleArray multipliedBy(DoubleArray other); DoubleArray dividedBy(DoubleArray other); DoubleArray combine(DoubleArray other, DoubleBinaryOperator operator); double combineReduce(DoubleArray other, DoubleTernaryOperator operator); DoubleArray concat(double... arrayToConcat); DoubleArray concat(DoubleArray arrayToConcat); DoubleArray sorted(); double min(); double max(); double sum(); double reduce(double identity, DoubleBinaryOperator operator); @Override MetaBean metaBean(); boolean equalWithTolerance(DoubleArray other, double tolerance); boolean equalZeroWithTolerance(double tolerance); @Override boolean equals(Object obj); @Override int hashCode(); @Override String toString(); static final DoubleArray EMPTY; }### Answer:
@Test public void test_filled() { assertContent(DoubleArray.filled(0)); assertContent(DoubleArray.filled(3), 0d, 0d, 0d); }
@Test public void test_filled_withValue() { assertContent(DoubleArray.filled(0, 1.5)); assertContent(DoubleArray.filled(3, 1.5), 1.5, 1.5, 1.5); }