diff --git a/Tests/HelperTests/BillingTest.cs b/Tests/HelperTests/BillingTest.cs
index 1612c4e..2a5f3e8 100644
--- a/Tests/HelperTests/BillingTest.cs
+++ b/Tests/HelperTests/BillingTest.cs
@@ -255,87 +255,101 @@ namespace Tests.HelperTests {
 
         [Test]
         [Ignore("Not implemented yet")]
-        public async Task Test_04_ComplexNotStrictAreaComs() {
+        public Task Test_04_ComplexNotStrictAreaComs() {
             // TODO
+            return Task.CompletedTask;
         }
 
         [Test]
         [Ignore("Not implemented yet")]
-        public async Task Test_05_ComplexNotStrictAreaComs_HonorGebunden() {
+        public Task Test_05_ComplexNotStrictAreaComs_HonorGebunden() {
             // TODO
+            return Task.CompletedTask;
         }
 
         [Test]
         [Ignore("Not implemented yet")]
-        public async Task Test_06_StrictAreaComs_NoFillLower_NotAllowed() {
+        public Task Test_06_StrictAreaComs_NoFillLower_NotAllowed() {
             // TODO
+            return Task.CompletedTask;
         }
 
         [Test]
         [Ignore("Not implemented yet")]
-        public async Task Test_07_StrictAreaComs_NoFillLower_Allowed() {
+        public Task Test_07_StrictAreaComs_NoFillLower_Allowed() {
             // TODO
+            return Task.CompletedTask;
         }
 
         [Test]
         [Ignore("Not implemented yet")]
-        public async Task Test_08_StrictAreaComs_NoFillLower_Allowed_AvoidUnderDeliveries() {
+        public Task Test_08_StrictAreaComs_NoFillLower_Allowed_AvoidUnderDeliveries() {
             // TODO
+            return Task.CompletedTask;
         }
 
         [Test]
         [Ignore("Not implemented yet")]
-        public async Task Test_09_StrictAreaComs_FillLowerUntilObligation_NotAllowed() {
+        public Task Test_09_StrictAreaComs_FillLowerUntilObligation_NotAllowed() {
             // TODO
+            return Task.CompletedTask;
         }
 
         [Test]
         [Ignore("Not implemented yet")]
-        public async Task Test_10_StrictAreaComs_FillLowerUntilObligation_Allowed() {
+        public Task Test_10_StrictAreaComs_FillLowerUntilObligation_Allowed() {
             // TODO
+            return Task.CompletedTask;
         }
 
         [Test]
         [Ignore("Not implemented yet")]
-        public async Task Test_11_StrictAreaComs_FillLowerUntilObligation_Allowed_AvoidUnderDeliveries() {
+        public Task Test_11_StrictAreaComs_FillLowerUntilObligation_Allowed_AvoidUnderDeliveries() {
             // TODO
+            return Task.CompletedTask;
         }
 
 
         [Test]
         [Ignore("Not implemented yet")]
-        public async Task Test_12_StrictAreaComs_FillLowerUntilObligation_NotAllowed() {
+        public Task Test_12_StrictAreaComs_FillLowerUntilObligation_NotAllowed() {
             // TODO
+            return Task.CompletedTask;
         }
 
         [Test]
         [Ignore("Not implemented yet")]
-        public async Task Test_13_StrictAreaComs_FillLowerUntilObligation_Allowed() {
+        public Task Test_13_StrictAreaComs_FillLowerUntilObligation_Allowed() {
             // TODO
+            return Task.CompletedTask;
         }
 
         [Test]
         [Ignore("Not implemented yet")]
-        public async Task Test_14_StrictAreaComs_FillLowerUntilObligation_Allowed_AvoidUnderDeliveries() {
+        public Task Test_14_StrictAreaComs_FillLowerUntilObligation_Allowed_AvoidUnderDeliveries() {
             // TODO
+            return Task.CompletedTask;
         }
 
         [Test]
         [Ignore("Not implemented yet")]
-        public async Task Test_15_StrictAreaComs_FillLowerUntilRight_NotAllowed() {
+        public Task Test_15_StrictAreaComs_FillLowerUntilRight_NotAllowed() {
             // TODO
+            return Task.CompletedTask;
         }
 
         [Test]
         [Ignore("Not implemented yet")]
-        public async Task Test_16_StrictAreaComs_FillLowerUntilRight_Allowed() {
+        public Task Test_16_StrictAreaComs_FillLowerUntilRight_Allowed() {
             // TODO
+            return Task.CompletedTask;
         }
 
         [Test]
         [Ignore("Not implemented yet")]
-        public async Task Test_17_StrictAreaComs_FillLowerUntilRight_Allowed_AvoidUnderDeliveries() {
+        public Task Test_17_StrictAreaComs_FillLowerUntilRight_Allowed_AvoidUnderDeliveries() {
             // TODO
+            return Task.CompletedTask;
         }
     }
 }