@Override
 public int hashCode() {
   final int prime = 31;
   int result = 1;
   result = prime * result + ((affectedCtxId == null) ? 0 : affectedCtxId.hashCode());
   result = prime * result + ((myContextType == null) ? 0 : myContextType.hashCode());
   result = prime * result + ((myPrivacyType == null) ? 0 : myPrivacyType.hashCode());
   result = prime * result + ((pref == null) ? 0 : pref.hashCode());
   result = prime * result + ((requestor == null) ? 0 : requestor.hashCode());
   return result;
 }
 @Override
 public boolean equals(Object obj) {
   if (this == obj) return true;
   if (obj == null) return false;
   if (getClass() != obj.getClass()) return false;
   PPNPrivacyPreferenceTreeModel other = (PPNPrivacyPreferenceTreeModel) obj;
   if (affectedCtxId == null) {
     if (other.affectedCtxId != null) return false;
   } else if (!affectedCtxId.equals(other.affectedCtxId)) return false;
   if (myContextType == null) {
     if (other.myContextType != null) return false;
   } else if (!myContextType.equals(other.myContextType)) return false;
   if (myPrivacyType != other.myPrivacyType) return false;
   if (pref == null) {
     if (other.pref != null) return false;
   } else if (!pref.equals(other.pref)) return false;
   if (requestor == null) {
     if (other.requestor != null) return false;
   } else if (!requestor.equals(other.requestor)) return false;
   return true;
 }