Index: dam classic/trunk/src/Deltares.DeltaModel/DikeLocation.cs
===================================================================
diff -u -r190 -r230
--- dam classic/trunk/src/Deltares.DeltaModel/DikeLocation.cs	(.../DikeLocation.cs)	(revision 190)
+++ dam classic/trunk/src/Deltares.DeltaModel/DikeLocation.cs	(.../DikeLocation.cs)	(revision 230)
@@ -2,7 +2,6 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.ComponentModel;
-using System.Diagnostics.Contracts;
 using System.Linq;
 using System.Xml.Serialization;
 using Deltares.Geographic;
@@ -908,12 +907,10 @@
         {
             get
             {
-                Contract.Assume(piezometricHeads != null);
                 return piezometricHeads;
             }
             set
             {
-                Contract.Ensures(PiezometricHeads != null);
                 if (value != null)
                 {
                     this.SetAndNotify2(out piezometricHeads, value, dl => dl.PiezometricHeads);