public void Pack(PackArgs args)
        {
            string filename = args.Nuspec;

            FileStream stream = new FileStream(filename, FileMode.Open);
            XDocument nuspec = XDocument.Load(stream);

            IXmlNamespaceResolver resolver = CreateNamespaceResolver();

            string id = nuspec.XPathSelectElement("nuget:package/nuget:metadata/nuget:id", resolver).Value;
            string version = nuspec.XPathSelectElement("nuget:package/nuget:metadata/nuget:version", resolver).Value;

            Uri partUri = PackUriHelper.CreatePartUri(new Uri("/" + id + ".nuspec", UriKind.Relative));

            string packagePath = id + "." + version + ".nupkg";

            using (Package package = Package.Open(packagePath, FileMode.Create))
            {
                PackagePart packagePart = package.CreatePart(partUri, MediaTypeNames.Text.Xml);

                using (XmlWriter writer = XmlWriter.Create(packagePart.GetStream(), new XmlWriterSettings { Indent = true }))
                {
                    nuspec.WriteTo(writer);
                }
            }
        }
        public void Pack(PackArgs args)
        {
            string filename = args.Nuspec;

            FileStream stream = new FileStream(filename, FileMode.Open);
            XDocument  nuspec = XDocument.Load(stream);

            IXmlNamespaceResolver resolver = CreateNamespaceResolver();

            string id      = nuspec.XPathSelectElement("nuget:package/nuget:metadata/nuget:id", resolver).Value;
            string version = nuspec.XPathSelectElement("nuget:package/nuget:metadata/nuget:version", resolver).Value;

            Uri partUri = PackUriHelper.CreatePartUri(new Uri("/" + id + ".nuspec", UriKind.Relative));

            string packagePath = id + "." + version + ".nupkg";

            using (Package package = Package.Open(packagePath, FileMode.Create))
            {
                PackagePart packagePart = package.CreatePart(partUri, MediaTypeNames.Text.Xml);

                using (XmlWriter writer = XmlWriter.Create(packagePart.GetStream(), new XmlWriterSettings {
                    Indent = true
                }))
                {
                    nuspec.WriteTo(writer);
                }
            }
        }