public SelectValueMapper<K> getMapper() {
    return mapper;
  }
@Test
  public void shouldBuildMapperWithCorrectExpressions() {
    // When:
    final SelectValueMapper<String> mapper = selection.getMapper();

    // Then:
    final List<SelectInfo> selectInfos = mapper.getSelects();
    assertThat(
        selectInfos.get(0).getEvaluator().getExpression(),
        equalTo(EXPRESSION1));
    assertThat(
        selectInfos.get(1).getEvaluator().getExpression(),
        equalTo(EXPRESSION2));
  }