/** @return investigator in registration. */
 public Person getPrimaryInvestigator() {
   return registration.getPrimaryRegistration() == null
       ? null
       : registration.getPrimaryRegistration().getProfile().getPerson();
 }
 /** @return primary registration id. */
 public Long getPrimaryRegistrationId() {
   return registration.getPrimaryRegistration() == null
       ? null
       : registration.getPrimaryRegistration().getId();
 }