BitSetIntSet extends GridSerializableCollection<Integer> implements IntSet { @Override public boolean contains(Object o) { if (o == null) throw new NullPointerException("Null values are not supported!"); return contains((int)o); } BitSetIntSet();  BitSetIntSet(int initCap);  BitSetIntSet(int initCap, Collection<Integer> coll); @Override int size(); @Override boolean contains(Object o); @Override boolean contains(int element); @NotNull @Override Iterator<Integer> iterator(); @Override boolean add(Integer integer); @Override boolean add(int element); @Override boolean remove(Object o); @Override boolean remove(int element); @Override int[] toIntArray(); @Override boolean containsAll(@NotNull Collection<?> c); @Override boolean addAll(@NotNull Collection<? extends Integer> c); @Override boolean retainAll(@NotNull Collection<?> c); @Override boolean removeAll(@NotNull Collection<?> c); @Override void clear();  }
@Test public void testContains() { IntSet intSet = new BitSetIntSet(); intSet.add(Integer.valueOf(1)); intSet.add(10); intSet.add(10); intSet.add(11); intSet.add(1025); assertTrue(intSet.contains(1)); assertFalse(intSet.contains(2)); assertFalse(intSet.contains(3)); assertFalse(intSet.contains(4)); assertTrue(intSet.contains(10)); assertTrue(intSet.contains(11)); assertFalse(intSet.contains(1024)); assertTrue(intSet.contains(1025)); }