### Question:
InOperator implements Predicate<T> { @Override public boolean test(T item) { return item != null && !collection.isEmpty() && new Chain<>(collection, configuration) .apply(removeNulls()) .flatMap(toObservableFromIterable()) .any(hasComparatorTestPassed(item)) .blockingGet(); } InOperator(Collection<T> collection,
               BiPredicate<T, T> comparator,
               InternalConfiguration configuration); @Override boolean test(T item);  }### Answer:
@Test public void testWithValidCollectionAndValidItemThenReturnTrue() { Collection<Integer> collection = Arrays.asList(1, 2, 3, 4); InternalConfiguration config = getInstance("testWithValidCollectionAndValidItemThenReturnTrue"); assertTrue(new InOperator<>(collection, new IsEqualComparator<Integer>(), config).test(2)); }
@Test public void testWithValidCollectionAndInvalidItemThenReturnFalse() { Collection<Integer> collection = Arrays.asList(1, 2, 3, 4); InternalConfiguration config = getInstance("testWithValidCollectionAndInvalidItemThenReturnFalse"); assertFalse(new InOperator<>(collection, new IsEqualComparator<Integer>(), config).test(5)); }
@Test public void testWithValidCollectionAndNullItemThenReturnFalse() { Collection<Integer> collection = Arrays.asList(1, 2, 3, 4); InternalConfiguration config = getInstance("testWithValidCollectionAndNullItemThenReturnFalse"); assertFalse(new InOperator<>(collection, new IsEqualComparator<Integer>(), config).test(null)); }
@Test public void testWithNullCollectionAndValidItemThenReturnFalse() { InternalConfiguration config = getInstance("testWithNullCollectionAndValidItemThenReturnFalse"); assertFalse(new InOperator<>(null, new IsEqualComparator<Integer>(), config).test(2)); }