private EquivalentAddressGroup toTarget(final ServiceInstance instance) {
            final String host = instance.getHost();
            final int port = getGrpcPort(instance);
            final Attributes attributes = getAttributes(instance);
            log.debug("Found gRPC server {}:{} for {}", host, port, getName());
            return new EquivalentAddressGroup(new InetSocketAddress(host, port), attributes);
        }
Do the actual update checks and resolving logic.

@return The new service instance list that is used to connect to the gRPC server or null if the old ones
        should be used.
grpc-client-spring-boot-starter/src/main/java/net/devh/boot/grpc/client/nameresolver/DiscoveryClientNameResolver.java