Index: Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Merge/AssessmentSectionMergeHandler.cs
===================================================================
diff -u -r7c6b0a809f0c14f6192e9518a92192bf59aafd15 -re35ffc492405e22b041aee22033f7ebc4b942036
--- Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Merge/AssessmentSectionMergeHandler.cs	(.../AssessmentSectionMergeHandler.cs)	(revision 7c6b0a809f0c14f6192e9518a92192bf59aafd15)
+++ Ringtoets/Integration/src/Ringtoets.Integration.Plugin/Merge/AssessmentSectionMergeHandler.cs	(.../AssessmentSectionMergeHandler.cs)	(revision e35ffc492405e22b041aee22033f7ebc4b942036)
@@ -75,47 +75,31 @@
             this.viewCommands = viewCommands;
         }
 
-        public void PerformMerge(AssessmentSection targetAssessmentSection, AssessmentSection sourceAssessmentSection,
-                                 IEnumerable<IFailureMechanism> failureMechanismsToMerge)
+        public void PerformMerge(AssessmentSection targetAssessmentSection, AssessmentSectionMergeData mergeData)
         {
             if (targetAssessmentSection == null)
             {
                 throw new ArgumentNullException(nameof(targetAssessmentSection));
             }
 
-            if (sourceAssessmentSection == null)
+            if (mergeData == null)
             {
-                throw new ArgumentNullException(nameof(sourceAssessmentSection));
+                throw new ArgumentNullException(nameof(mergeData));
             }
 
-            if (failureMechanismsToMerge == null)
-            {
-                throw new ArgumentNullException(nameof(failureMechanismsToMerge));
-            }
-
             BeforeMerge(targetAssessmentSection);
 
             var changedObjects = new List<IObservable>
             {
                 targetAssessmentSection
             };
 
-            changedObjects.AddRange(MergeHydraulicBoundaryLocations(targetAssessmentSection, sourceAssessmentSection));
-            MergeFailureMechanisms(targetAssessmentSection, failureMechanismsToMerge);
+            changedObjects.AddRange(MergeHydraulicBoundaryLocations(targetAssessmentSection, mergeData.AssessmentSection));
+            MergeFailureMechanisms(targetAssessmentSection, mergeData.FailureMechanisms);
 
             AfterMerge(changedObjects);
         }
 
-        public void PerformMerge(AssessmentSection targetAssessmentSection, AssessmentSectionMergeData mergeData)
-        {
-            if (mergeData == null)
-            {
-                throw new ArgumentNullException(nameof(mergeData));
-            }
-
-            PerformMerge(targetAssessmentSection, mergeData.AssessmentSection, mergeData.FailureMechanisms);
-        }
-
         private void BeforeMerge(AssessmentSection assessmentSection)
         {
             viewCommands.RemoveAllViewsForItem(assessmentSection);
@@ -156,7 +140,7 @@
         }
 
         private static IEnumerable<IObservable> MergeHydraulicBoundaryLocationCalculations(IEnumerable<HydraulicBoundaryLocationCalculation> targetCalculations,
-                                                                       IEnumerable<HydraulicBoundaryLocationCalculation> sourceCalculations)
+                                                                                           IEnumerable<HydraulicBoundaryLocationCalculation> sourceCalculations)
         {
             for (var i = 0; i < targetCalculations.Count(); i++)
             {