public void Test_EmbedImage_filepath_cid()
        {
            var filename = Path.GetTempFileName();
            var cid      = "*****@*****.**";
            var mail     = BasicMailBuilder
                           .EmbedImage(filename, cid)
                           .Build();

            var message = new SendGridMessage();

            message.AddAttachment(filename);
            message.EmbedImage(new FileInfo(filename).Name, cid);

            CollectionAssert.AreEquivalent(message.GetEmbeddedImages().ToList(), mail.GetEmbeddedImages().ToList());
            CollectionAssert.AreEquivalent(message.Attachments, mail.Attachments);
            CollectionAssert.AreEquivalent(message.StreamedAttachments, mail.StreamedAttachments);
        }
        public void Test_EmbedImage_linkedresource()
        {
            var filename       = Path.GetTempFileName();
            var attachment     = new Attachment(filename);
            var linkedResource = new LinkedResource(filename);

            var mail = BasicMailBuilder
                       .EmbedImage(linkedResource)
                       .Build();

            var message = new SendGridMessage();

            message.AddAttachment(attachment.ContentStream, attachment.Name);
            message.EmbedImage(linkedResource.ContentId, linkedResource.ContentId);
            CollectionAssert.AreEquivalent(message.GetEmbeddedImages().ToList(), mail.GetEmbeddedImages().ToList());
            Assert.AreEqual(1, message.StreamedAttachments.Count);
            Assert.AreEqual(1, mail.StreamedAttachments.Count);
            Assert.AreEqual(message.StreamedAttachments.First().Value.Length, mail.StreamedAttachments.First().Value.Length);
        }