/// <summary>
        /// using Microsoft.Extensions.DependencyInjection;
        /// </summary>
        /// <returns></returns>
        public IActionResult GeteServicesInFunction()
        {
            StringBuilder stringBuilder = new StringBuilder();

            //sms
            ISms smsService = HttpContext.RequestServices.GetService <ISms>();

            stringBuilder.Append(smsService.SmsSend() + " \n");

            //mails
            IEnumerable <IMail> mailServices = HttpContext.RequestServices.GetServices <IMail>();

            foreach (var mail in mailServices)
            {
                stringBuilder.Append(mail.Send() + "\n");
            }

            //file Converter
            IFileConverter fileConverterService = HttpContext.RequestServices.GetService <IFileConverter>();                                    //v1
            Func <string, IFileConverter> fileConverterServiceDelg = HttpContext.RequestServices.GetService <Func <string, IFileConverter> >(); //v2

            stringBuilder.Append(fileConverterService.Convert());                                                                               //v1
            ///stringBuilder.Append(fileConverterServiceDelg("XmlConverter").Convert());//v2

            return(Content(stringBuilder.ToString()));
        }
        public IActionResult Index()
        {
            StringBuilder stringBuilder = new StringBuilder();

            //sms
            stringBuilder.Append(_sms.SmsSend() + " \n");

            //mails
            ///var mailA = _mails.First(o =>o is MailA);
            ///var mailA = _mails.First(o => o.GetType() == typeof(MailA));
            //or
            ///var mailA = _mails.First(o => o.GetType().Name.Equals("MailA"));
            foreach (var mail in _mails)
            {
                stringBuilder.Append(mail.Send() + "\n");
            }

            //file Converter
            stringBuilder.Append(_fileConverter.Convert());//v1
            ///stringBuilder.Append(_fileConverterDelg("XmlConverter").Convert());//v2


            return(Content(stringBuilder.ToString()));
        }