@Override
    public <T> CompletableFuture<T> newContextAwareFuture(RequestContext ctx) {
        return new Java12ContextAwareFuture<>(requireNonNull(ctx, "ctx"));
    }
Implementation of {@link JavaVersionSpecific} using Java 12 APIs.
core/src/main/java12/com/linecorp/armeria/internal/common/Java12VersionSpecific.java