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