/** api to update appointment status to signed */
 public void sign() {
   setApptStatus(SIGNED);
   Hib.template().update(this);
 }
 /**
  * static method for removing an instance from the database
  *
  * @param apptClient id of appointment to remove
  */
 public static void removeInstance(final ApptClient apptClient) {
   Hib.template().delete(apptClient);
 }
 /** public interface to set status to checked out */
 public void checkout() {
   setApptStatus(CHECKED_OUT);
   Hib.template().update(this);
 }
 /**
  * factory method for instance from the database
  *
  * @param apptId the appointment id
  * @return an instance from the database or null
  */
 public static ApptClient getInstance(final Integer apptId) {
   return Hib.template().get(ApptClient.class, apptId);
 }
 /** public interface to set status to checked in */
 public void checkin() {
   setApptStatus(CHECKED_IN);
   this.setCheckinTime(new Date());
   Hib.template().update(this);
 }