@Override
 public Object[] getChildren(Object parentElement) {
   if (parentElement instanceof MongoDBCollectionInfoDTO) {
     MongoDBCollectionInfoDTO dto = (MongoDBCollectionInfoDTO) parentElement;
     return dto.getChild().toArray();
   }
   return null;
 }
  @Override
  public boolean hasChildren(Object element) {
    if (element instanceof MongoDBCollectionInfoDTO) {
      MongoDBCollectionInfoDTO info = (MongoDBCollectionInfoDTO) element;

      return info.getChild().size() > 0;
    }
    return false;
  }