class VoicePrint implements Serializable {

    void merge(double[] features) {
        if(this.features.length != features.length) {
            throw new IllegalArgumentException("Features of new VoicePrint is of different size : [" + 
                    features.length + "] expected [" + this.features.length + "]");
        }
        w.lock();
        try { 
            merge(this.features, features);
            meanCount++;
        } 
        finally { w.unlock(); }
    }

      VoicePrint();
      VoicePrint(double[] features);
      VoicePrint(VoicePrint print);

}