@Test
 void sizeTest() {
   final HopscotchCollection<Integer> hopscotchCollection = new HopscotchCollection<>();
   Assert.assertEquals(hopscotchCollection.size(), 0);
   hopscotchCollection.addAll(testVals);
   Assert.assertEquals(hopscotchCollection.size(), testVals.size());
   hopscotchCollection.add(notInTestVals);
   Assert.assertEquals(hopscotchCollection.size(), testVals.size() + 1);
   hopscotchCollection.removeEach(notInTestVals);
   Assert.assertEquals(hopscotchCollection.size(), testVals.size());
   hopscotchCollection.clear();
   Assert.assertEquals(hopscotchCollection.size(), 0);
 }
 @Test
 void clearTest() {
   final HopscotchCollection<Integer> hopscotchCollection = new HopscotchCollection<>(testVals);
   hopscotchCollection.clear();
   Assert.assertEquals(hopscotchCollection.size(), 0);
   Assert.assertEquals(SVUtils.iteratorSize(hopscotchCollection.iterator()), 0);
 }
 @Test
 void addTest() {
   final HopscotchCollection<Integer> hopscotchCollection =
       new HopscotchCollection<>(testVals.size());
   testVals.stream().forEach(hopscotchCollection::add);
   Assert.assertEquals(hopscotchCollection.size(), testVals.size());
   Assert.assertTrue(hopscotchCollection.containsAll(testVals));
 }
 @Test
 void resizeTest() {
   final HopscotchCollection<Integer> hopscotchCollection = new HopscotchCollection<>(1);
   final int N_ENTRIES = 1000000;
   for (int idx = 0; idx != N_ENTRIES; ++idx) {
     hopscotchCollection.add(idx);
   }
   Assert.assertEquals(hopscotchCollection.size(), N_ENTRIES);
   Assert.assertEquals(hopscotchCollection.stream().mapToInt(i -> i).min().orElse(-1), 0);
   Assert.assertEquals(
       hopscotchCollection.stream().mapToInt(i -> i).max().orElse(-1), N_ENTRIES - 1);
 }
 @Test
 void iteratorTest() {
   final HopscotchCollection<Integer> hopscotchCollection = new HopscotchCollection<>(testVals);
   Assert.assertEquals(SVUtils.iteratorSize(hopscotchCollection.iterator()), testVals.size());
   final Integer KEY_TO_REMOVE = 1;
   final Iterator<Integer> itr1 = hopscotchCollection.iterator();
   while (itr1.hasNext()) {
     if (itr1.next().equals(KEY_TO_REMOVE)) itr1.remove();
   }
   final int onesCount = (int) testVals.stream().filter(i -> i.equals(KEY_TO_REMOVE)).count();
   Assert.assertEquals(hopscotchCollection.size(), testVals.size() - onesCount);
   Assert.assertEquals(
       SVUtils.iteratorSize(hopscotchCollection.iterator()), hopscotchCollection.size());
   final Iterator<Integer> itr2 = hopscotchCollection.iterator();
   while (itr2.hasNext()) {
     itr2.next();
     itr2.remove();
   }
   Assert.assertTrue(hopscotchCollection.isEmpty());
   Assert.assertEquals(
       SVUtils.iteratorSize(hopscotchCollection.iterator()), hopscotchCollection.size());
 }
 @Test
 void createFromCollectionTest() {
   final HopscotchCollection<Integer> hopscotchCollection = new HopscotchCollection<>(testVals);
   Assert.assertEquals(hopscotchCollection.size(), testVals.size());
   Assert.assertTrue(hopscotchCollection.containsAll(testVals));
 }