class ConfigChangedEvent extends EventObject {

    @Override
    public String toString() {
        return "ConfigChangedEvent{" +
                "key='" + key + '\'' +
                ", group='" + group + '\'' +
                ", content='" + content + '\'' +
                ", changeType=" + changeType +
                "} " + super.toString();
    }

    public  ConfigChangedEvent(String key, String group, String content);
    public  ConfigChangedEvent(String key, String group, String content, ConfigChangeType changeType);

}