add test for this

Author: marticliment

src/UniGetUI.PackageEngine.Serializable.Tests/TestSerializableInstallationOptions.cs

@@ -27,6 +27,8 @@ public void ToAndFromJsonNode(bool a, bool b, string c, string d, string e, stri
             Version = l
         };
 
+        Assert.Equal(a, originalObject1.DiffersFromDefault());
+
         var object2 = new SerializableInstallationOptions();
         string contents = originalObject1.AsJsonString();
         Assert.NotEmpty(contents);