Maciek refactor works + delete unnecesery interface (conception changed)

buisnesslogic/src/main/java/com/plannaplan/services/GroupService.java

@@ -1,6 +1,7 @@
 package com.plannaplan.services;
 
 import java.util.List;
+import java.util.Optional;
 
 import com.plannaplan.entities.Groups;
 import com.plannaplan.repositories.GroupRepository;
@@ -16,7 +17,7 @@ public class GroupService {
     public GroupService() {
     }
 
-    public Groups find(int time, int capacity, String room) {
+    public Optional<Groups> find(int time, int capacity, String room) {
         return this.repo.find(time, room, capacity);
     }
 
@@ -24,15 +25,16 @@ public class GroupService {
         return this.repo.getByCourse(id);
     }
 
-    public void save(Groups group) {
+    public Groups save(Groups group) {
         this.repo.save(group);
+        return group;
     }
 
-    public void delete(Groups groups){
+    public void delete(Groups groups) {
         this.repo.delete(groups);
     }
 
-    public int getGroupsAmmount(){
-        return (int)this.repo.count();
+    public int getGroupsAmmount() {
+        return (int) this.repo.count();
     }
 }