/// <summary>
        /// Gets required service. Throws exception if such is not found or there are no registered services.
        /// </summary>
        /// <typeparam name="TInstance">Type of requested service.</typeparam>
        /// <returns>Instance of TInstance type.</returns>
        public static TInstance GetRequiredService <TInstance>()
        {
            ServiceValidator.ValidateServices();
            var service = Current.GetService <TInstance>();

            ServiceValidator.ValidateServiceExists(service);
            return(service);
        }