@Test
    @SetSystemProperty(key = "com.linecorp.armeria.preferredIpV4Addresses", value = "10.0.0.0/8")
    void systemPropertyPreferredIpV4Addresses() throws Throwable {
        assertFlags("preferredIpV4Addresses").isNotNull();
    }
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