Set whether or not this delegate should render its row line through \
        the tree area.
        
        :return     <state>

def setExtendsTree( self, state ):
        """
        Set whether or not this delegate should render its row line through \
        the tree area.
        
        :return     <state>
        """
        delegate = self.itemDelegate()
        if ( isinstance(delegate, XTreeWidgetDelegate) ):
            delegate.setExtendsTree(state)