Index: Ringtoets/Integration/src/Ringtoets.Integration.Service/Merge/AssessmentSectionProviderActivity.cs
===================================================================
diff -u -rc7a1a30a7fafe8671a06b10bf2a3d56cf9f510a4 -reb36d0a34bdea2d82aabec9f649516dac00a648a
--- Ringtoets/Integration/src/Ringtoets.Integration.Service/Merge/AssessmentSectionProviderActivity.cs	(.../AssessmentSectionProviderActivity.cs)	(revision c7a1a30a7fafe8671a06b10bf2a3d56cf9f510a4)
+++ Ringtoets/Integration/src/Ringtoets.Integration.Service/Merge/AssessmentSectionProviderActivity.cs	(.../AssessmentSectionProviderActivity.cs)	(revision eb36d0a34bdea2d82aabec9f649516dac00a648a)
@@ -1,8 +1,14 @@
-using Core.Common.Base.Service;
+using System;
+using Core.Common.Base.Service;
+using Ringtoets.Integration.Data;
 using Ringtoets.Integration.Data.Merge;
 
 namespace Ringtoets.Integration.Service.Merge
 {
+    /// <summary>
+    /// Activity to retrieve a collection of <see cref="AssessmentSection"/>
+    /// from a file.
+    /// </summary>
     public class AssessmentSectionProviderActivity : Activity
     {
         private readonly AssessmentSectionsOwner owner;
@@ -11,10 +17,35 @@
 
         private bool canceled;
 
+        /// <summary>
+        /// Creates a new instance of <see cref="AssessmentSectionProviderActivity"/>.
+        /// </summary>
+        /// <param name="owner">The owner to set the retrieved collection
+        /// of <see cref="AssessmentSection"/> on.</param>
+        /// <param name="assessmentSectionProvider">The provider defining how to
+        /// retrieve the collection of <see cref="AssessmentSection"/> from a file.</param>
+        /// <param name="filePath">The file path to retrieve the collection of
+        /// <see cref="AssessmentSection"/> from.</param>
+        /// <exception cref="ArgumentNullException">Thrown when any of the arguments is <c>null</c>.</exception>
         public AssessmentSectionProviderActivity(AssessmentSectionsOwner owner,
                                                  IAssessmentSectionProvider assessmentSectionProvider,
                                                  string filePath)
         {
+            if (owner == null)
+            {
+                throw new ArgumentNullException(nameof(owner));
+            }
+
+            if (assessmentSectionProvider == null)
+            {
+                throw new ArgumentNullException(nameof(assessmentSectionProvider));
+            }
+
+            if (filePath == null)
+            {
+                throw new ArgumentNullException(nameof(filePath));
+            }
+
             this.owner = owner;
             this.assessmentSectionProvider = assessmentSectionProvider;
             this.filePath = filePath;