@Test
public void testDemoQuery() throws Exception {

    PipelineConfig conf = PipelineConfig.fromYamlFile(
            "src/test/resources/tiny_conf.yaml"
    );
    BasicBatchPipeline p = new BasicBatchPipeline(conf);
    Explanation e = p.results();
    assertEquals(3.0, e.numTotal(), 1e-10);
}