internal async Task <MimeFile> GetCertificate(string id) { var existing = cache.Get <MimeFile>(id); if (existing == null) { var data = await tableStore.GetRow <CertificateEntity>(TABLE_NAME, id); if (data != null) { existing = RenderCertificate(data); cache.Set(data.RowKey, existing, TimeSpan.FromMinutes(30)); } } return(existing); }