assertEquals(0, oemBytes.length, "OEM bytes should be empty");
        }

        @Test
        @DisplayName("Round-trip encoding/decoding should preserve string content")
        void testRoundTripConversion() {
            // Given
            String[] testStrings = { "Simple ASCII", "Unicode: 世界 🌍", "Mixed: ASCII + Unicode ñöt", "Special chars: !@#$%^&*()", "" };

            for (String original : testStrings) {