/** @return invitation status text with date. */
 public String getInvitationStatusText() {
   String key = registration.getInvitation().getInvitationStatus().getKey() + ".with.date";
   String[] args = {dateFormat.format(registration.getInvitation().getInvitationChangeDate())};
   return action.getText(key, args);
 }
 /** @return the invitation status object. */
 public InvitationStatus getInvitationStatus() {
   return registration.getInvitation().getInvitationStatus();
 }