Index: Ringtoets/Piping/test/Ringtoets.Piping.Data.TestUtil.Test/TestPipingFailureMechanismTest.cs
===================================================================
diff -u -r66b07e7599319ea71ff109d8303f74a4a2e5f71c -rc290911dd4647e3115e239c8baf814717c098a5a
--- Ringtoets/Piping/test/Ringtoets.Piping.Data.TestUtil.Test/TestPipingFailureMechanismTest.cs	(.../TestPipingFailureMechanismTest.cs)	(revision 66b07e7599319ea71ff109d8303f74a4a2e5f71c)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Data.TestUtil.Test/TestPipingFailureMechanismTest.cs	(.../TestPipingFailureMechanismTest.cs)	(revision c290911dd4647e3115e239c8baf814717c098a5a)
@@ -21,7 +21,6 @@
 
 using System.Collections.Generic;
 using System.Linq;
-using Core.Common.Base;
 using Core.Common.Base.Geometry;
 using NUnit.Framework;
 using Ringtoets.Common.Data.FailureMechanism;
@@ -52,7 +51,7 @@
             // Assert
             Assert.AreEqual(24, failureMechanism.Contribution);
 
-            ObservableUniqueItemCollectionWithSourcePath<RingtoetsPipingSurfaceLine> surfaceLines = failureMechanism.SurfaceLines;
+            RingtoetsPipingSurfaceLineCollection surfaceLines = failureMechanism.SurfaceLines;
             Assert.AreEqual("path/to/surfaceLines", surfaceLines.SourcePath);
             Assert.AreEqual(1, surfaceLines.Count);
             RingtoetsPipingSurfaceLine[] surfaceLineArray = surfaceLines.ToArray();