@Test
public void invokeDurationNanosMillis() {

    FunctionTestUtil.assertResult(stringFunction.invoke(Duration.ofNanos(25)), "PT0.000000025S");
    FunctionTestUtil.assertResult(stringFunction.invoke(Duration.ofNanos(10000)), "PT0.00001S");
    FunctionTestUtil.assertResult(stringFunction.invoke(Duration.ofNanos(10025)), "PT0.000010025S");
    FunctionTestUtil.assertResult(stringFunction.invoke(Duration.ofMillis(1500)), "PT1.5S");
    FunctionTestUtil.assertResult(stringFunction.invoke(Duration.ofMillis(90061025)), "P1DT1H1M1.025S");
    FunctionTestUtil.assertResult(stringFunction.invoke(Duration.ofMillis(-90061025)), "-P1DT1H1M1.025S");
}