@SuppressWarnings("MissingOverride") // For compilation with Java < 9.
    public void setHandshakeApplicationProtocolSelector(
            final BiFunction<SSLEngine, List<String>, String> selector) {
        this.selector = selector;
        setApplicationProtocolSelector(toApplicationProtocolSelector(selector));
    }
A wrapper around {@link ConscryptEngine} that adapts to the new Java 9 (and potentially later
patches of 8) {@code setHandshakeApplicationProtocolSelector} API (which requires Java 8 for
compilation, due to the use of {@link BiFunction}).
common/src/main/java/org/conscrypt/Java8EngineWrapper.java