public boolean add(final Integer value)
    {
        return add(value.intValue());
    }
@Test
    void forEachShouldInvokeConsumerWithTheMissingValueAtTheIfOneWasAddedToTheSet()
    {
        @SuppressWarnings("unchecked") final Consumer<Integer> consumer = mock(Consumer.class);

        testSet.add(MISSING_VALUE);
        testSet.add(15);
        testSet.add(MISSING_VALUE);

        testSet.forEach(consumer);

        final InOrder inOrder = inOrder(consumer);
        inOrder.verify(consumer).accept(15);
        inOrder.verify(consumer).accept(MISSING_VALUE);
        verifyNoMoreInteractions(consumer);
    }