I Can JSON Interface with Implementation

ICanJSON.cs

using Newtonsoft.Json;

namespace myproject
{
    public interface ICanJson
    {
        // marker
    }

    public static class JsonExtensions
    {
        /// <summary>
        /// ToJSON
        /// </summary>
        /// <param name="obj"></param>
        /// <returns></returns>
        public static string ToJson(this ICanJson obj)
        {
            return JsonConvert.SerializeObject(obj);
        }

        /// <summary>
        /// ToJSONFormatted
        /// </summary>
        /// <param name="obj"></param>
        /// <returns></returns>
        public static string ToJsonFormatted(this ICanJson obj)
        {
            return JsonConvert.SerializeObject(obj, Formatting.Indented);
        }
    }

}