Index: Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Create/PersistenceRegistryTest.cs
===================================================================
diff -u -re42bdf3dd379c46bab9212eb7b30f4754c9bc91c -r9ee8f17742a5407fd9453aeb12f20cfedb20c73e
--- Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Create/PersistenceRegistryTest.cs	(.../PersistenceRegistryTest.cs)	(revision e42bdf3dd379c46bab9212eb7b30f4754c9bc91c)
+++ Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Create/PersistenceRegistryTest.cs	(.../PersistenceRegistryTest.cs)	(revision 9ee8f17742a5407fd9453aeb12f20cfedb20c73e)
@@ -25,6 +25,8 @@
 using Application.Ringtoets.Storage.TestUtil;
 using Core.Common.Base.Geometry;
 using NUnit.Framework;
+using Ringtoets.ClosingStructures.Data;
+using Ringtoets.ClosingStructures.Data.TestUtil;
 using Ringtoets.Common.Data.DikeProfiles;
 using Ringtoets.Common.Data.FailureMechanism;
 using Ringtoets.GrassCoverErosionInwards.Data;
@@ -638,6 +640,67 @@
             Assert.IsFalse(result);
         }
 
+        [Test]
+        public void Contains_WithoutClosingStructure_ThrowsArgumentNullException()
+        {
+            // Setup
+            var registry = new PersistenceRegistry();
+
+            // Call
+            TestDelegate call = () => registry.Contains((ClosingStructure)null);
+
+            // Assert
+            string paramName = Assert.Throws<ArgumentNullException>(call).ParamName;
+            Assert.AreEqual("model", paramName);
+        }
+
+        [Test]
+        public void Contains_ClosingStructureAdded_ReturnsTrue()
+        {
+            // Setup
+            ClosingStructure closingStructure = new TestClosingStructure();
+            var registry = new PersistenceRegistry();
+            registry.Register(new ClosingStructureEntity(), closingStructure);
+
+            // Call
+            bool result = registry.Contains(closingStructure);
+
+            // Assert
+            Assert.IsTrue(result);
+        }
+
+        [Test]
+        public void Contains_OtherClosingStructureAdded_ReturnsFalse()
+        {
+            // Setup
+            ClosingStructure closingStructure = new TestClosingStructure();
+
+            ClosingStructure otherStructure = new TestClosingStructure();
+            var registry = new PersistenceRegistry();
+            registry.Register(new ClosingStructureEntity(), otherStructure);
+
+            // Call
+            bool result = registry.Contains(closingStructure);
+
+            // Assert
+            Assert.IsFalse(result);
+        }
+
+        [Test]
+        public void Contains_NoClosingStructureAdded_ReturnsFalse()
+        {
+            // Setup
+            ClosingStructure closingStructure = new TestClosingStructure();
+
+            var registry = new PersistenceRegistry();
+
+            // Call
+            bool result = registry.Contains(closingStructure);
+
+            // Assert
+            Assert.IsFalse(result);
+        }
+
         #endregion
 
         #region Get methods