public <T> CompletableFuture<T> newContextAwareFuture(RequestContext ctx) {
        return new ContextAwareFuture<>(requireNonNull(ctx, "ctx"));
    }
Returns a {@link CompletableFuture} which executes all callbacks with the {@link RequestContext}.
core/src/main/java/com/linecorp/armeria/internal/common/JavaVersionSpecific.java