XPCNativeWrapper and getData (application/x-moz-node)

Another basic DOM/syntax  query?

I am attempting to drag and drop iframe HTML table rows using ancestor 
addEventListeners

Dragstart issues setData using x-moz-node to copy the dragstart event 
element (htmltablerowelement)

So ondrop  node reports that an HTML table row has been passed but not as we 
know it!

What then is the syntax to extract the html node in a XPCNativeWrapper so 
that it can be appended after  the target element?

Is it a method.| property.. or what?

........... or am I using a the wrong data transfer type????


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 function onDragDrop(event)
{
 var node=event.dataTransfer.getData("application/x-moz-node");

alert("node"+node)                 // [object XPCNativeWrapper [ object
HTMLTableRowElement]]
alert(node.tagName)            //  undefined

}