@Before
    public void setUp() {
        strings = new ArrayList<>();
        strings.add("0");
        strings.add("1");
        strings.add("2");
        strings.add("3");
        strings.add("4");
        strings.add("5");
    }
Tests that PeekableListIterator behaves as expected.

@author Einar M R Rosenvinge
document/src/test/java/com/yahoo/document/annotation/PeekableListIteratorTestCase.java