@Test
    void test() {
        final GrpcChannelProperties properties = this.grpcChannelsProperties.getChannel("test");
        assertEquals(Duration.ofSeconds(-1), properties.getShutdownGracePeriod());
    }
Tests whether the property resolution works with negative values and without suffixes.
grpc-client-spring-boot-starter/src/test/java/net/devh/boot/grpc/client/config/GrpcChannelPropertiesNegativeNoUnitTest.java