diff --git a/FabAccessAPI_Test/FabAccessAPITests.cs b/FabAccessAPI_Test/FabAccessAPITests.cs
index ba7a683..f669bbd 100644
--- a/FabAccessAPI_Test/FabAccessAPITests.cs
+++ b/FabAccessAPI_Test/FabAccessAPITests.cs
@@ -6,6 +6,7 @@ using Capnp;
 using Capnp.Rpc;
 using log4net.Config;
 using Microsoft.Extensions.Logging;
+using static FabAccessAPI.Schema.Machine.WriteInterface;
 
 namespace FabAccessAPI_Test {
     public class Tests {
@@ -84,11 +85,16 @@ namespace FabAccessAPI_Test {
             Machine testmachine = await machines.GetMachine("Testmachine");
             Assert.NotNull(testmachine);
 
-            await testmachine.Use();
+            IGiveBack giveBack = await testmachine.Use();
 
             FabAccessAPI.Schema.Machine.MInfo minfo = await testmachine.GetMInfo();
             Assert.NotNull(minfo);
             Assert.AreEqual(FabAccessAPI.Schema.State.inUse, minfo.State);
+
+            //await giveBack.Ret();
+            //minfo = await testmachine.GetMInfo();
+            //Assert.NotNull(minfo);
+            //Assert.AreEqual(FabAccessAPI.Schema.State.free, minfo.State);
         }
     }
 }
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