static int linuxMajorVersion0(String version, boolean isLinux) {
        if (!isLinux) {
            return -1;
        }

        String[] versionTokens = version.split("\\.");
        try {
            return Integer.parseInt(versionTokens[0]);
        } catch (NumberFormatException e) {
            return -1;
        }
    }
@Test
    public void test_linuxMajorVersion0_whenIsLinux() {
        assertEquals(5, OS.linuxMajorVersion0("5.16.12-200.fc35.x86_64", true));
    }