Optimizely custom visitor group model and criteria classes

CookieVisitorGroup.cs

using EPiServer.Personalization.VisitorGroups;
using System.Security.Principal;
using System.Web;

namespace Foundation.Personalization.Criteria.CookieExistsWithValue
{
    [VisitorGroupCriterion(
        Category = "Custom",
        DisplayName = "Cookie Exists with Value",
        Description = "Evaluates if a visitor has a cookie with a specific value")]
    public class CookieWithValue : CriterionBase<CookieWithValueModel>
    {
        public override bool IsMatch(IPrincipal principal, HttpContextBase httpContext)
        {
            return (httpContext.Request.Cookies[Model.CookieName] != null &&
                httpContext.Request.Cookies[Model.CookieName].Value == Model.CookieValue);
        }
    }
}

CookieVisitorGroupModel.cs

using EPiServer.Personalization.VisitorGroups;

namespace Foundation.Personalization.Criteria.CookieExistsWithValue
{
    public class CookieWithValueModel : CriterionModelBase
    {
        public string CookieName { get; set; }
        public string CookieValue { get; set; }

        public override ICriterionModel Copy()
        {
            return ShallowCopy();
        }
    }
}