@Test
public void testIsSortable() {

    IndexImpl<Node> index = generateEmptyIndex();
    Column ageCol = index.columnStore.getColumn("age");
    Column bigIntCol = index.columnStore.getColumn("big_int");
    Column fooCol = index.columnStore.getColumn("foo");
    Assert.assertTrue(index.isSortable(ageCol));
    Assert.assertTrue(index.isSortable(bigIntCol));
    Assert.assertFalse(index.isSortable(fooCol));
}