CbrtFunction implements Function<Double> { @Override public Double apply(List<Object> objects) { return Math.cbrt(Double.valueOf(String.valueOf(objects.get(0)))); }  @Override Set<String> validateInput(List<Object> args); @Override Class<Double> getReturnType(); @Override FunctionName getName(); @Override Double apply(List<Object> objects); @Override String getSignature(); @Override String getDescription();  }
@Test public void apply() throws Exception { assertThat(function.apply(Collections.singletonList(8)), equalTo(2d)); }