code: public void moveLastChild( Row newParent )
  	{
  		if( this == newParent )
  			return;
  
  		// remove from its current position
  		Row parentItem = m_parent;
  		if( parentItem == null )
  			parentItem = this.treeTable.m_rootItem;
  		parentItem.getChilds().remove( this );
  		// DOM.removeChild( m_body, m_tr );
  
  		if( newParent == null )
  			newParent = this.treeTable.m_rootItem;
  
  		// insert at the end of the current parent
  
  		// DOM add
  		Row lastLeaf = newParent.getLastLeaf();
  		Element trToInsertAfter = lastLeaf.m_tr;
  		if( trToInsertAfter != null )
  		{
  			int after = DOM.getChildIndex( this.treeTable.m_body, trToInsertAfter );
  			int before = after + 1;
  
  			DOM.insertChild( this.treeTable.m_body, m_tr, before );
  		}
  		else
  		{
  			DOM.appendChild( this.treeTable.m_body, m_tr );
  		}
  
  		parentItem.getChilds().add( this );
  
  		// take care of the left padding
  		Element firstTd = DOM.getChild( m_tr, 0 );
  		firstTd.getStyle().setPaddingLeft( getLevel() * this.treeTable.treePadding, Unit.PX );
  	}
docs: move to be the last item of parent