String[] fields = { "sort1", "sort2", "sort3" };
        queryFieldConfig.setSortFields(fields);

        assertSame(fields, queryFieldConfig.sortFields);
    }

    public void test_constants() {
        // Test that constants have expected values
        assertEquals("score", QueryFieldConfig.SCORE_FIELD);
        assertEquals("_score", QueryFieldConfig.DOC_SCORE_FIELD);

  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester
  public void testForPredicateSerializable() {
    checkCanReserialize(Functions.forPredicate(Predicates.equalTo(5)));
  }

  public void testConstant() {
    Function<@Nullable Object, Object> f = Functions.<Object>constant("correct");
    assertEquals("correct", f.apply(new Object()));
    assertEquals("correct", f.apply(null));

  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester
  public void testForPredicateSerializable() {
    checkCanReserialize(Functions.forPredicate(Predicates.equalTo(5)));
  }

  public void testConstant() {
    Function<@Nullable Object, Object> f = Functions.<Object>constant("correct");
    assertEquals("correct", f.apply(new Object()));
    assertEquals("correct", f.apply(null));