@Test
    @SetSystemProperty(key = "com.linecorp.armeria.defaultPreferHttp1", value = "true")
    void defaultPreferHttp1() throws Throwable {
        assertFlags("defaultPreferHttp1").isEqualTo(true);
    }
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