How do we Register the class in Rule Engine for creating custom code?

[sugeshshun]

We are trying to create custom method in rule engine. As per the document we need to register the class (Utils) to call the custom method

I have tried like below, but am not sure my class is registered or not?
"Expression": "Utils.CheckContains(input1.country, "india,usa,canada,France") == true"

[peeveen]

It's described here.
When you create the RulesEngine, pass in a ReSettings object containing a CustomTypes definition that contains your Utils class type. You can then use the methods in that class in your expressions.

var reSettingsWithCustomTypes = new ReSettings { CustomTypes = new Type[] { typeof(Utils) } };
new RulesEngine.RulesEngine(workflowRules.ToArray(), null, reSettingsWithCustomTypes);