@Test
public void test_nested_to_string() {

  Aggregator avgAggregator = dsl.avg(dsl.multiply(DSL.ref("integer_value", INTEGER),
      DSL.literal(ExprValueUtils.integerValue(10))));
  assertEquals(String.format("avg(*(%s, %d))", DSL.ref("integer_value", INTEGER), 10),
      avgAggregator.toString());
}