update

src/java/lodge/reservationsystem/CabinReservation.java

@@ -3,7 +3,7 @@ package lodge.reservationsystem;
 import java.time.ZonedDateTime;
 import java.time.temporal.ChronoUnit;
 
-public final class CabinReservation extends Reservation implements IReservation{
+public final class CabinReservation extends Reservation {
 
   CabinReservation(){
     super();

src/java/lodge/reservationsystem/HotelReservation.java

@@ -3,7 +3,7 @@ package lodge.reservationsystem;
 import java.time.ZonedDateTime;
 import java.time.temporal.ChronoUnit;
 
-public final class HotelReservation extends Reservation implements IReservation {
+public final class HotelReservation extends Reservation {
 
   HotelReservation() {
     super();

src/java/lodge/reservationsystem/HouseReservation.java

@@ -3,7 +3,7 @@ package lodge.reservationsystem;
 import java.time.ZonedDateTime;
 import java.time.temporal.ChronoUnit;
 
-public final class HouseReservation extends Reservation implements IReservation{
+public final class HouseReservation extends Reservation {
 
   HouseReservation(){
     super();

src/java/lodge/reservationsystem/IReservation.java

@@ -1,5 +0,0 @@
-package lodge.reservationsystem;
-
-public interface IReservation {
-
-}

src/java/lodge/reservationsystem/Reservation.java

@@ -244,9 +244,7 @@ public abstract class Reservation{
 
     }
 
-    
     public abstract String ReservationType();
-    public abstract boolean checkValid() throws ReservationException;
     public abstract float calculatePrice();
-
+    public abstract boolean checkValid() throws ReservationException;
 }