public String get(final Object key) {
    if (this._current.containsKey(key)) {
      return this._current.get(key);
    } else if (this._parent != null) {
      return this._parent.get(key);
    } else {
      return null;
    }
  }
Return value if available in current Props otherwise return from parent
dss-appconn/appconns/dss-eventchecker-appconn/src/main/java/com/webank/wedatasphere/dss/appconn/eventchecker/utils/Props.java