[HttpGet]
        public async Task<IActionResult> GetPDF(/*some arguments*/)
        {
            /*
            Here I get images (as byte arrays) and captions from the
            database

            Then I want to create a pdf and loop over the images and
            alternate adding a caption and an image to the pdf
            */
            using (var streamPdf = new MemoryStream())
            {
                //Next line saves pdf to memorystream so it can be sent
                document.Save(streamPdf);
                return File(streamPdf.ToArray(), "application/pdf");
            }

        }