@Test
    @SetSystemProperty(key = "com.linecorp.armeria.useOpenSsl", value = "false")
    @SetSystemProperty(key = "com.linecorp.armeria.tlsEngineType", value = "OPENSSL")
    void tlsEngineTypeIsUsedWhenIncompatibleWithUseOpenSsl() {
        assertThat(Flags.tlsEngineType()).isEqualTo(TlsEngineType.OPENSSL);
    }
Makes sure OpenSSL SSLEngine is used instead of JDK SSLEngine while running tests
on Linux, Windows and OS X.
core/src/test/java/com/linecorp/armeria/common/FlagsTest.java