@LiteralParameters("x")
    @ScalarOperator(NOT_EQUAL)
    @SqlType(StandardTypes.BOOLEAN)
    @SqlNullable
    public static Boolean notEqual(@SqlType("varchar(x)") Slice left, @SqlType("varchar(x)") Slice right)
    {
        return !left.equals(right);
    }
@Test
    public void testNotEqual()
    {
        assertFunction("'foo' <> 'foo'", BOOLEAN, false);
        assertFunction("'foo' <> 'bar'", BOOLEAN, true);
        assertFunction("'bar' <> 'foo'", BOOLEAN, true);
        assertFunction("'bar' <> 'bar'", BOOLEAN, false);
    }