The code of Method publishConfig of Class ConsulDynamicConfiguration:
```java
    @Override
    public boolean publishConfig(String key, String group, String content) throws UnsupportedOperationException {
        String normalizedKey = convertKey(group, key);
        return kvClient.putValue(normalizedKey + PATH_SEPARATOR + content);
    }
```
We want put a config with value with the "content", but the method just add the "content" to the key and put a null value.
private void initKVCache() {
            this.kvCache = KVCache.newCache(kvClient, normalizedKey);
            kvCache.addListener(this);
            kvCache.start();
        }
        @Override
        public void notify(Map<String, Value> newValues) {
            
            
            Optional<Value> newValue = newValues.values().stream()
                    .filter(value -> value.getKey().equals(normalizedKey))
                    .findAny();
            newValue.ifPresent(value -> {
                
                Optional<String> decodedValue = newValue.get().getValueAsString();
                decodedValue.ifPresent(v -> listeners.forEach(l -> {
                    ConfigChangedEvent event = new ConfigChangedEvent(key, group, v, ConfigChangeType.MODIFIED);
                    l.process(event);
                }));
            });
        }
        private void addListener(ConfigurationListener listener) {
            this.listeners.add(listener);
        }
        private void removeListener(ConfigurationListener listener) {
            this.listeners.remove(listener);
        }
    }
}