@Test
public void testFallback() {

    parameters.add(ff2.literal("abc12_67"));
    parameters.add(ff2.literal(".*(\\d{3})_(\\d{3})"));
    parameters.add(ff2.literal("first${1}_second${2}_full${0}"));
    parameters.add(ff2.literal("noMatch"));
    Function fn = finder.findFunction("stringTemplate", parameters, fallback);
    Object result = fn.evaluate(null);
    assertEquals("noMatch", result);
}