@Test public void testGetRequiredColumns() { AndDimFilter andDimFilter = new AndDimFilter( Lists.newArrayList( new SelectorDimFilter("a", "d", null), new SelectorDimFilter("b", "d", null), new SelectorDimFilter("c", "d", null) ) ); Assert.assertEquals(andDimFilter.getRequiredColumns(), Sets.newHashSet("a", "b", "c")); } }