@Test
public void testIndexNodeNullValue() {

    ColumnStore<Node> columnStore = generateBasicNodeColumnStore();
    IndexStore<Node> indexStore = columnStore.indexStore;
    IndexImpl<Node> mainIndex = indexStore.mainIndex;
    Column col1 = columnStore.getColumn("foo");
    Column col2 = columnStore.getColumn("age");
    NodeImpl n = new NodeImpl("0");
    n.setAttribute(col1, null);
    n.setAttribute(col2, null);
    indexStore.index(n);
    Assert.assertEquals(mainIndex.count(col1, null), 1);
    Assert.assertEquals(mainIndex.count(col2, null), 1);
    Assert.assertEquals(mainIndex.countElements(col1), 1);
    Assert.assertEquals(mainIndex.countElements(col2), 1);
    Assert.assertEquals(mainIndex.countValues(col1), 1);
    Assert.assertEquals(mainIndex.countValues(col2), 1);
    Assert.assertTrue(mainIndex.values(col1).contains(null));
    Assert.assertTrue(mainIndex.values(col2).contains(null));
    Assert.assertSame(getIterable(mainIndex.get(col1, null))[0], n);
}