private int countLayerPropertiesModified() {
   int count = 0;
   System.out.println("Memento Counting: ");
   System.out.println("Memento Counting: " + this.modifiedLayersMap.values());
   for (AbstractMementoOriginalProperties memento : this.modifiedLayersMap.values()) {
     System.out.println("Memento changed: " + memento.isChanged());
     if (memento.isChanged()) {
       count++;
     }
   }
   return count;
 }
 private void prepareLayerPropertiesModified() {
   for (AbstractMementoOriginalProperties memento : this.modifiedLayersMap.values()) {
     if (memento.isChanged()) {
       this.add(memento);
     }
   }
   this.modifiedLayersMap.clear();
 }