public static BaseFilterOperator getAndFilterOperator(QueryContext queryContext,
      List<BaseFilterOperator> filterOperators, int numDocs) {
    return _instance.getAndFilterOperator(queryContext, filterOperators, numDocs);
  }
@Test(dataProvider = "priorities")
  public void testPriority(BaseFilterOperator highPriorty, BaseFilterOperator lowerPriorty) {
    ArrayList<BaseFilterOperator> unsorted = Lists.newArrayList(lowerPriorty, highPriorty);
    BaseFilterOperator filterOperator =
        FilterOperatorUtils.getAndFilterOperator(QUERY_CONTEXT, unsorted, NUM_DOCS);
    assertTrue(filterOperator instanceof AndFilterOperator);
    List<Operator> actualChildOperators = ((AndFilterOperator) filterOperator).getChildOperators();
    assertEquals(actualChildOperators, Lists.newArrayList(highPriorty, lowerPriorty), "Filter " + highPriorty
        + " should have more priority than filter " + lowerPriorty);
  }