@LiteralParameters("x")
    @ScalarOperator(LESS_THAN_OR_EQUAL)
    @SqlType(StandardTypes.BOOLEAN)
    public static boolean lessThanOrEqual(@SqlType("varchar(x)") Slice left, @SqlType("varchar(x)") Slice right)
    {
        return left.compareTo(right) <= 0;
    }
@Test
    public void testLessThanOrEqual()
    {
        assertFunction("'foo' <= 'foo'", BOOLEAN, true);
        assertFunction("'foo' <= 'bar'", BOOLEAN, false);
        assertFunction("'bar' <= 'foo'", BOOLEAN, true);
        assertFunction("'bar' <= 'bar'", BOOLEAN, true);
    }