builder = new DefaultMessageBuilder();
        format.formatRate(builder, 1000000.0);
        assertEquals("1.0 MB/s", builder.build());
    }

    @Test
    void testFormatRateLargeValues() {
        FileSizeFormat format = new FileSizeFormat();

        // Test large but valid rates
        MessageBuilder builder = new DefaultMessageBuilder();
        format.formatRate(builder, 5e12); // 5 TB/s