decreased visibility of group-fields -> adapted tests and GroupService

src/main/java/mops/gruppen2/domain/Aggregate.java

@@ -1,15 +1,23 @@
 package mops.gruppen2.domain;
 
+import lombok.Getter;
 import mops.gruppen2.domain.event.Event;
 
 import java.lang.reflect.Method;
 
 public abstract class Aggregate {
 
+    @Getter
+    protected final long id;
+
+    protected Aggregate(long id) {
+        this.id = id;
+    }
+
     /**
      * Ruft die spezifische applyEvent-Methode im entsprechenden Aggregat auf.
      *
-     * @param event
+     * @param event Einzelne Änderung an dem Aggregat
      */
     public void applyEvent(Event event) {
         try {

src/main/java/mops/gruppen2/domain/Group.java

@@ -12,14 +12,13 @@ import java.util.Map;
 @EqualsAndHashCode(callSuper=false)
 @Getter
 public class Group extends Aggregate {
-	long id;
-	String title;
-	String description;
-	List<User> members;
-	Map<User, Role> roles;
+	private String title;
+	private String description;
+	private List<User> members;
+	private Map<User, Role> roles;
 
-	private void applyEvent(CreateGroupEvent event){
-		this.id = event.getGroup_id();
+	public Group(CreateGroupEvent event) {
+		super(event.getGroup_id());
 		this.title = event.getGroupTitle();
 		this.description = event.getGroupDescription();
 		this.members = new ArrayList<>();