public Duration getShutdownGracePeriod() {
        return this.shutdownGracePeriod == null ? DEFAULT_SHUTDOWN_GRACE_PERIOD : this.shutdownGracePeriod;
    }
Gets the time to wait for the channel to gracefully shutdown. If set to a negative value, the channel waits
forever. If set to {@code 0} the channel will force shutdown immediately. Defaults to {@code 30s}.

@return The time to wait for a graceful shutdown.
grpc-client-spring-boot-starter/src/main/java/net/devh/boot/grpc/client/config/GrpcChannelProperties.java