@Description("cube root")
    @ScalarFunction
    @SqlType(StandardTypes.DOUBLE)
    public static double cbrt(@SqlType(StandardTypes.DOUBLE) double num)
    {
        return Math.cbrt(num);
    }
@Test
    public void testCbrt()
    {
        for (double doubleValue : DOUBLE_VALUES) {
            assertFunction("cbrt(" + doubleValue + ")", DOUBLE, Math.cbrt(doubleValue));
            assertFunction("cbrt(REAL '" + (float) doubleValue + "')", DOUBLE, Math.cbrt((float) doubleValue));
        }
        assertFunction("cbrt(NULL)", DOUBLE, null);
    }