test(InteractionOutput): add additional tests

test/core/interaction_output_test.dart

@@ -64,5 +64,27 @@ void main() {
       final value2 = await interactionOutput.value();
       expect(value1, value2);
     });
+
+    test(
+        "throw a NotReadableException when calling the arrayBuffer() method "
+        "twice", () async {
+      final contentSerdes = ContentSerdes();
+      final content = Content(
+        "text/plain",
+        const Stream.empty(),
+      );
+
+      final interactionOutput = InteractionOutput(
+        content,
+        contentSerdes,
+        Form(Uri.parse("http://example.org")),
+        const DataSchema(),
+      );
+
+      await interactionOutput.arrayBuffer();
+
+      final result = interactionOutput.arrayBuffer();
+      await expectLater(result, throwsA(isA<NotReadableException>()));
+    });
   });
 }