private void WriteNavigationLink(ODataWriter writer, Lazy<ODataReader> lazyReader, ODataNavigationLink link)
        {
            this.WriteStart(writer, link);
            var expanded = link.GetAnnotation<ODataNavigationLinkExpandedItemObjectModelAnnotation>();
            if (expanded != null)
            {
                var feed = expanded.ExpandedItem as ODataFeed;
                if (feed != null)
                {
                    this.WriteFeed(writer, lazyReader, feed);
                }
                else
                {
                    ODataEntry entry = expanded.ExpandedItem as ODataEntry;
                    if (entry != null || expanded.ExpandedItem == null)
                    {
                        this.WriteEntry(writer, lazyReader, entry);
                    }
                    else
                    {
                        ExceptionUtilities.Assert(expanded.ExpandedItem is ODataEntityReferenceLink, "Content of a nav. link can only be a feed, entry or entity reference link.");
                        writer.WriteEntityReferenceLink((ODataEntityReferenceLink)expanded.ExpandedItem);
                    }
                }
            }

            this.WriteEnd(writer, ODataReaderState.NavigationLinkEnd);
            this.Read(lazyReader);
        }