@Test
public void testSubstituteSpecificVars() throws Exception {

    Map<String, Object> fieldsAndValues = new HashMap<>();
    fieldsAndValues.put("1", "one");
    fieldsAndValues.put("2", "${1} plus ${1}");
    fieldsAndValues.put("3", "${1} plus two");
    StreamlineEvent event = StreamlineEventImpl.builder().fieldsAndValues(fieldsAndValues).dataSourceId("dsrcid").build();
    TransformRuntime transformRuntime = new SubstituteTransformRuntime(new SubstituteTransform(Collections.singleton("3")));
    List<StreamlineEvent> result = transformRuntime.execute(event);
    assertEquals(1, result.size());
    assertEquals(3, result.get(0).size());
    assertEquals("one", result.get(0).get("1"));
    assertEquals("${1} plus ${1}", result.get(0).get("2"));
    assertEquals("one plus two", result.get(0).get("3"));
}