public int topicCountQuota() {
        try {
            String topicCountQuota = currentControllerConfig().get(QuotaConfigs.CLUSTER_QUOTA_TOPIC_COUNT_CONFIG);
            if (topicCountQuota == null) {
                topicCountQuota = staticConfig.get(QuotaConfigs.CLUSTER_QUOTA_TOPIC_COUNT_CONFIG).toString();
            }
            return Integer.parseInt(topicCountQuota);
        } catch (Exception ignore) {
            return Integer.MAX_VALUE;
        }
    }
Get the config value for the give topic and give config key.
If the config value is not found, return null.

@param topicName            The topic name for the config.
@param configKey            The key for the config.
metadata/src/main/java/org/apache/kafka/controller/ConfigurationControlManager.java