private <T> void assertFailedShutdown(final AtomicReference<Future<T>> request) {
        final Status status = assertFutureThrowsStatus(UNAVAILABLE, request.get(), A_BIT_TIME, MILLISECONDS);
        assertThat(status.getDescription()).contains("shutdownNow");
    }
Tests for {@link InProcessChannelFactory}'s shutdown behavior using an in-process server/channel.
tests/src/test/java/net/devh/boot/grpc/test/shutdown/GrpcChannelLifecycleWithCallsTest.java