assertEquals(3, bytesRead); // Only 3 bytes available
    }

    @Test
    @DisplayName("readn should handle EOF correctly")
    void testReadnEOF() throws IOException {
        byte[] buffer = new byte[10];
        ByteArrayInputStream bais = new ByteArrayInputStream(new byte[0]);

        int bytesRead = SessionServicePacket.readn(bais, buffer, 0, 5);