public IActionResult Index(IFormFile[] files)
        {
            IEnumerable <IFormFile> csvFiles = files.Where(file => Path.GetExtension(file.FileName) == ".csv");
            var model = new FilesProcessingViewModel();

            if (csvFiles.Any())
            {
                using (var processor = new CsvProcessor(_context, _logger))
                {
                    var filesForProcessing = csvFiles.Select(formFile => new InputFile
                    {
                        FileName   = formFile.FileName,
                        OpenStream = formFile.OpenReadStream
                    });
                    model.Result = processor.ProcessFiles(filesForProcessing);
                }
            }
            else
            {
                model.Result = "There isn't csv-files";
            }
            return(View("FilesProcessing", model));
        }