How do I fix stackoverflowexception issue?

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C#

testing

API

serialization

Hello I am doing functional API testing. This error occurred when I am trying to serialize my json payload. When I try to run my test I get the following error
"The active test run was aborted. Reason: Test host process crashed : Process is terminated due to StackOverflowException"
My helper method worked fine but I believe it has a infinite recursion somewhere. Here is the break down of the different classes I have.
I have one helper class and using custom ContractResolver I am picking the methods name and the attributes I want to apply to and then using my custom serialize method. Please any helper from any c# expert who be highly appreciated!

public class Helper
    {
        public void Asserts(HttpWebResponse response)
        {
            Assert.AreEqual(HttpStatusCode.OK, response.StatusCode);
        }


        [AttributeUsage(AttributeTargets.Property)]
        public class UseWithApiMethodsAttribute : Attribute
        {
            public UseWithApiMethodsAttribute(params string[] methodNames)
            {
                MethodNames = methodNames;
            }

            public string[] MethodNames { get; private set; }
        }

        public class SelectivePropertyResolver : DefaultContractResolver
        {
            public string ApiMethodName { get; private set; }

            public SelectivePropertyResolver(string apiMethodName)
            {
                ApiMethodName = apiMethodName;
            }

            protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
            {
                JsonProperty prop = base.CreateProperty(member, memberSerialization);
                if (member.MemberType == MemberTypes.Property)
                {
                    var att = ((PropertyInfo)member).GetCustomAttribute<UseWithApiMethodsAttribute>(true);
                    if (att == null || !att.MethodNames.Contains(ApiMethodName))
                    {
                        prop.Ignored = true;
                    }
                }
                return prop;
            }
        }

        public string SerializeForApiMethod(Object model, string methodName)
        {
            var settings = new JsonSerializerSettings
            {
                ContractResolver = new SelectivePropertyResolver(methodName),
                Formatting = Formatting.Indented
            };
            return JsonConvert.SerializeObject(model, settings);
        }
    }

Here is my Model class called TagModel where I am using the get and set and assigning the values

public class TagModel
    {

        public TagModel defaultModel = new TagModel
        {
            endpointIds = new List<int> { -2147483612, -2147483611 },
            tagIds = new List<int> { 35, 37 },
            id = -2147483639,
            parentId = 37,
            nodeId = 1,
            oldParentId = null,
            isEndpoint = false,
            state = 2,
            destinationTag = 2,

        };

        public TagModel modelForUpdate = new TagModel
        {
            tagNode = new TagModel.TagNode
            {
                query = null,
                type = 0,
                filter = null,
                ldapPaths = null,
                editPermissions = 0,
                id = 0,
                disallowed = false,
                name = "NewTag"

            },
            parentId = 7
        
        };

        [UseWithApiMethods("UpdateTag")]
        public TagNode tagNode { get; set; }


        public class TagNode
        {
            [UseWithApiMethods("UpdateTag")]
            public object query { get; set; }
            [UseWithApiMethods("UpdateTag")]
            public int type { get; set; }
            [UseWithApiMethods("UpdateTag")]
            public object filter { get; set; }
            [UseWithApiMethods("UpdateTag")]
            public object ldapPaths { get; set; }
            [UseWithApiMethods("UpdateTag")]
            public int editPermissions { get; set; }
            [UseWithApiMethods("UpdateTag")]
            public int id { get; set; }
            [UseWithApiMethods("UpdateTag")]
            public bool disallowed { get; set; }
            [UseWithApiMethods("UpdateTag")]
            public string name { get; set; }
        }


        [UseWithApiMethods("UpdateTagToRoot")]
        public int nodeId { get; set; }
        [UseWithApiMethods("UpdateTagToRoot")]
        public object oldParentId { get; set; }
        [UseWithApiMethods("UpdateTagToRoot")]
        public bool isEndpoint { get; set; }
        [UseWithApiMethods("UpdateTagToRoot")]
        public int state { get; set; }
        [UseWithApiMethods("UpdateTagToRoot")]
        public int destinationTag { get; set; }




        [UseWithApiMethods("UpdateEndpointsToTags")]
        public List<int> endpointIds { get; set; }
        [UseWithApiMethods("UpdateEndpointsToTags")]
        public List<int> tagIds { get; set; }


        [UseWithApiMethods("UpdateEndpointsFromTags")]
        public int id { get; set; }
        [UseWithApiMethods("UpdateEndpointsFromTags", "UpdateTag")]
        public int parentId { get; set; }




    }


}

Lastly I have another class is where my fuction method called "Tags" is where I came calling the SerializeForApiMethod and passing the model class instance and the method name. This class is also inherting TagModel class

public class Tags : TagModel
    {
        public string BaseUrl = RequestHandler.GenerateRequestURL("svc-searchcontroller") + "Tag/";
        public Helper helper = new Helper();


        public HttpWebResponse UpdateTag()
        {
            RequestHandler requestor = new RequestHandler(BaseUrl + "UpdateTag", HttpVerb.POST, AuthenticationType.Bearer);
            return requestor.SendRequest(helper.SerializeForApiMethod(modelForUpdate, "UpdateTag"));
        }

   
     
    
        public HttpWebResponse UpdateEndpointsFromTags()
        {
            RequestHandler requestor = new RequestHandler(BaseUrl + "UpdateEndpointsFromTags", HttpVerb.POST, AuthenticationType.Bearer);
            return requestor.SendRequest(helper.SerializeForApiMethod(defaultModel, "UpdateEndpointsFromTags"));
        }

        public HttpWebResponse UpdateEndpointsToTags()
        {
            RequestHandler requestor = new RequestHandler(BaseUrl + "UpdateEndpointsToTags", HttpVerb.POST, AuthenticationType.Bearer);
            return requestor.SendRequest(helper.SerializeForApiMethod(defaultModel, "UpdateEndpointsToTags"));
        }

        public HttpWebResponse UpdateTagToRoot()
        {
            RequestHandler requestor = new RequestHandler(BaseUrl + "UpdateTagToRoot", HttpVerb.POST, AuthenticationType.Bearer);
            return requestor.SendRequest(helper.SerializeForApiMethod(defaultModel, "UpdateTagToRoot"));
        }

What I have tried:

After debugging the code, I see it throws the stackoverflow exception when I created the instance of Tagmodel class. When I said

public TagModel defaultModel = new TagModel