@Override
 public int hashCode() {
   int hash = uri == null ? 0 : uri.hashCode();
   hash = 37 * hash + expandLevel;
   for (OrganicMaterialEventConverter item : this.items) {
     hash = 37 * hash + item.hashCode();
   }
   return hash;
 }
 /**
  * Returns a collection OrganicMaterialEvents entities.
  *
  * @return a collection of OrganicMaterialEvents entities
  */
 @XmlTransient
 public Collection<OrganicMaterialEvent> getEntities() {
   entities = new ArrayList<OrganicMaterialEvent>();
   if (items != null) {
     for (OrganicMaterialEventConverter item : items) {
       entities.add(item.getEntity());
     }
   }
   return entities;
 }