System.IO.Packaging.Check.Package C# (CSharp) Method

        public static void Package(object package)
        {
            if (package == null)
                throw new ArgumentNullException(nameof(package));
        }

        protected internal PackagePart(Package package, Uri partUri, string contentType, CompressionOption compressionOption)
        {
            Check.Package(package);
            Check.PartUri(partUri);
            Check.ContentTypeIsValid(contentType);

            Package              = package;
            Uri                  = partUri;
            ContentType          = contentType;
            CompressionOption    = compressionOption;
            RelationshipsPartUri = PackUriHelper.GetRelationshipPartUri(Uri);
        }