### Question:
EmptyIntSet extends AbstractImmutableIntSet { @Override public Object[] toArray() { return new Object[0]; }  static IntSet getInstance(); @Override boolean contains(int i); @Override boolean containsAll(IntSet set); @Override int size(); @Override boolean isEmpty(); @Override boolean contains(Object o); @Override PrimitiveIterator.OfInt iterator(); @Override Object[] toArray(); @Override T[] toArray(T[] a); @Override boolean containsAll(Collection<?> c); @Override IntStream intStream(); @Override boolean equals(Object obj); @Override String toString();  }### Answer:
@Test public void testToArray() throws Exception { Object[] array = es.toArray(); assertEquals(0, array.length); }
@Test public void testToArray1() throws Exception { Object[] array = es.toArray(new Integer[1]); assertEquals(1, array.length); assertEquals(null, array[0]); array = es.toArray(new Integer[0]); assertEquals(0, array.length); }