private static void validateS3UlsInConfig(Context context, ApplicationContainerCluster cluster, boolean isExclusive) {
        if (hasS3UrlInConfig(cluster)) {
            // TODO: Would be even better if we could add which config/field the url is set for in the error message
            String message = "Found s3:// urls in config for container cluster " + cluster.getName();
            if ( ! context.deployState().zone().system().isPublic())
                context.illegal(message + ". This is only supported in public systems");
            else if ( ! isExclusive)
                context.illegal(message + ". Nodes in the cluster need to be 'exclusive'," +
                                " see https://docs.vespa.ai/en/reference/services.html#nodes");
        }
    }
Validates that config using s3:// urls is used in public system and with nodes that are exclusive.

@author hmusum
config-model/src/main/java/com/yahoo/vespa/model/application/validation/UrlConfigValidator.java