public FEELFnResult<Boolean> invoke(@ParameterName("list") List list) {
        if (list == null) {
            return FEELFnResult.ofResult(true);
        }
        boolean result = true;
        for (final Object element : list) {
            if (element != null && !(element instanceof Boolean)) {
                return FEELFnResult.ofError(new InvalidParametersEvent(Severity.ERROR, "an element in the list is not" +
                        " a Boolean"));
            } else {
                if (element != null) {
                    result &= (Boolean) element;
                }
            }
        }
        return FEELFnResult.ofResult(result);
    }
@Test
    void invokeListParamReturnTrue() {
        FunctionTestUtil.assertResult(nnAllFunction.invoke(Arrays.asList(Boolean.TRUE, Boolean.TRUE)), true);
    }