Checkpoint - group controller needs to be fixed

restservice/src/main/java/com/plannaplan/responses/mappers/GroupsMappers.java

@@ -0,0 +1,20 @@
+package com.plannaplan.responses.mappers;
+
+import java.util.List;
+import java.util.Objects;
+import java.util.stream.Collectors;
+
+import com.plannaplan.entities.Groups;
+import com.plannaplan.responses.models.DefaultGroupResponse;
+import com.plannaplan.responses.models.WithCapacityGroupResponse;
+
+public class GroupsMappers {
+    public static List<DefaultGroupResponse> mapToDefaultResponse(List<Groups> groups) {
+        return groups.stream().filter(Objects::nonNull).map(DefaultGroupResponse::new).collect(Collectors.toList());
+    }
+
+    public static List<WithCapacityGroupResponse> mapToCapacityResponse(List<Groups> groups) {
+        return groups.stream().filter(Objects::nonNull).map(WithCapacityGroupResponse::new)
+                .collect(Collectors.toList());
+    }
+}