@Override
    default <I, O> Listener<I> interceptCall(ServerCall<I, O> call, Metadata headers,
                                             ServerCallHandler<I, O> next) {
        return new DeferredListener<>(call, asyncInterceptCall(call, headers, next));
    }
Asynchronously intercepts {@link ServerCall} dispatch by the {@code next} {@link ServerCallHandler}.
grpc/src/main/java/com/linecorp/armeria/server/grpc/AsyncServerInterceptor.java