@Test
    void singleContextInjectionFromTestConfigurationTest() {
        assertNotNull(this.blockingStub, "blockingStub");
    }
Test should cover bean simple single bean creation with {@link GrpcClientBean} annotation with
{@link TestConfiguration}
tests/src/test/java/net/devh/boot/grpc/test/inject/GrpcClientBeanInjectionTest.java