/// <inheritdoc />
        public override Task <ProviderTimeZoneResult> DetermineProviderTimeZoneResult(HttpContext httpContext)
        {
            if (httpContext == null)
            {
                throw new ArgumentNullException(nameof(httpContext));
            }

            var value = httpContext.Request
                        .Query[this.QueryStringKey];

            if (string.IsNullOrEmpty(value))
            {
                return(RequestTimeZoneProvider.nullProviderTimeZoneResult);
            }

            var providerTimeZoneResult = new ProviderTimeZoneResult(value);

            return(Task.FromResult(providerTimeZoneResult));
        }
        /// <inheritdoc />
        public override Task <ProviderTimeZoneResult> DetermineProviderTimeZoneResult(HttpContext httpContext)
        {
            if (httpContext == null)
            {
                throw new ArgumentNullException(nameof(httpContext));
            }

            var value = httpContext.Request
                        .Cookies[CookieName];

            if (string.IsNullOrEmpty(value))
            {
                return(RequestTimeZoneProvider.nullProviderTimeZoneResult);
            }

            var providerTimeZoneResult = new ProviderTimeZoneResult(value.Replace("tz=", ""));

            return(Task.FromResult(providerTimeZoneResult));
        }