solving error in tests, using updated implementation of Property

test/unit_tests/message_test.dart

@@ -7,13 +7,13 @@ void mainMessageTests() {
     final List<SubmodelElement> inputList = <SubmodelElement>[
       Property<int>(idShort: 'a', value: 1),
       Property<bool>(idShort: 'b', value: true),
-      Property<String>(idShort: 'c', value: 'Hallo'),
-      //TODO: is this working?
-      Property<SubmodelElementCollection>(
-          idShort: 'pose',
-          value: SubmodelElementCollection(
-            idShort: 'pose',
-          )..elements = <SubmodelElement>[Property<int>(idShort: 'x', value: 1), Property<int>(idShort: 'y', value: 2)])
+      Property<String>(idShort: 'c', value: 'Hello'),
+      SubmodelElementCollection(
+            idShort: 'd',
+          )..elements = <SubmodelElement>[
+            Property<int>(idShort: 'x', value: 1), 
+            Property<int>(idShort: 'y', value: 2)
+            ]
     ];
     final I40InvokeOperationAsyncRequest requestMessage = I40InvokeOperationAsyncRequest(
       submodelId: 'mySubmodel',
@@ -31,22 +31,45 @@ void mainMessageTests() {
       expect(parsedRequestMessage.sender, 'mySender');
       expect(parsedRequestMessage.receiver, 'myReceiver');
       //TODO
-      // expect(parsedRequestMessage.inputMap['a'], 1);
-      // expect(parsedRequestMessage.inputMap['b'], true);
-      // expect(parsedRequestMessage.inputMap['c'], 'Hallo');
-      // expect(parsedRequestMessage.inputMap['d'], {'x': 1, 'y': 2});
+      expect(
+          (parsedRequestMessage.inputVariables.firstWhere(
+                      (SubmodelElement element) => element.idShort == 'a')
+                  as Property<int>)
+              .value,
+          1);
+       expect(
+          (parsedRequestMessage.inputVariables.firstWhere(
+                      (SubmodelElement element) => element.idShort == 'b')
+                  as Property<bool>)
+              .value,
+          true);
+       expect(
+          (parsedRequestMessage.inputVariables.firstWhere(
+                      (SubmodelElement element) => element.idShort == 'c')
+                  as Property<String>)
+              .value,
+          'Hello');
+       expect(
+          (parsedRequestMessage.inputVariables.firstWhere(
+                      (SubmodelElement element) => element.idShort == 'd')
+                  as SubmodelElementCollection)
+              .elements,
+          <SubmodelElement>[
+            Property<int>(idShort: 'x', value: 1), 
+            Property<int>(idShort: 'y', value: 2)
+            ]);
     }
 
     final List<SubmodelElement> outputList = <SubmodelElement>[
       Property<int>(idShort: 'a', value: 1),
       Property<bool>(idShort: 'b', value: true),
       Property<String>(idShort: 'c', value: 'Hallo'),
-      //TODO: is this working?
-      Property<SubmodelElementCollection>(
-          idShort: 'pose',
-          value: SubmodelElementCollection(
-            idShort: 'pose',
-          )..elements = <SubmodelElement>[Property<int>(idShort: 'x', value: 1), Property<int>(idShort: 'y', value: 2)])
+      SubmodelElementCollection(
+        idShort: 'd',
+      )..elements = <SubmodelElement>[
+          Property<int>(idShort: 'x', value: 1),
+          Property<int>(idShort: 'y', value: 2)
+        ]
     ];
     final I40InvokeOperationAsyncReply replyMsg = I40InvokeOperationAsyncReply(
         sender: 'mySender',
@@ -85,8 +108,8 @@ void mainMessageTests() {
         submodelElement: Property<String>(
             idShort: 'myElement',
             semanticId: Reference(
-                type: ReferenceType.ExternalReference,
-                keys: [ReferenceKey(type: ReferenceKeyType.GlobalReference, value: "mySemanticReference")]),
+                type: ReferenceTypes.ExternalReference,
+                keys: [ReferenceKey(type: ReferenceKeyTypes.GlobalReference, value: "mySemanticReference")]),
             value: 'myValue'));
 
     var parsedReplyMessage = I40Message.fromJson(replyMessage.toJson());