presto-main/src/main/java/io/prestosql/type/CharOperators.java/CharOperators/between
class CharOperators:    @LiteralParameters("x")
    @ScalarOperator(BETWEEN)
    @SqlType(StandardTypes.BOOLEAN)
    public static boolean between(@SqlType("char(x)") Slice value, @SqlType("char(x)") Slice min, @SqlType("char(x)") Slice max)
    {
        return compareChars(min, value) <= 0 && compareChars(value, max) <= 0;
    }