/// <summary>
        /// Retrieve service id from a layout action.
        /// </summary>
        /// <param name="action">An ActionInfo object.</param>
        /// <param name="apis">An ApiList object.</param>
        /// <returns>A service id.</returns>
        public static string GetActionService(
            this ActionInfo action,
            ApiList apis)
        {
            if (!action.IsValid() ||
                !apis.IsValid())
            {
                return(null);
            }

            var apiService = action.GetService();

            if (apiService.IsValid())
            {
                return(apis.GetApiListService(apiService));
            }

            return(null);
        }