code: function getNextSourceNode( node, startFromSibling, lastNode )
  	{
  		var next = node.getNextSourceNode( startFromSibling, null, lastNode );
  		while ( !bookmarkGuard( next ) )
  			next = next.getNextSourceNode( startFromSibling, null, lastNode );
  		return next;
  	}
docs: Get a reference for the next element, bookmark nodes are skipped.