Creates a connection between the currently selected \
        nodes, provided there are only 2 nodes selected.  If \
        the cls parameter is supplied then that will be the \
        class instance used when creating the connection. \
        Otherwise, the default connection class will be used.
        
        :param      cls         subclass of <XNodeConnection>
        
        :return     <XNodeConnection> || None

def connectSelection( self, cls = None ):
        """
        Creates a connection between the currently selected \
        nodes, provided there are only 2 nodes selected.  If \
        the cls parameter is supplied then that will be the \
        class instance used when creating the connection. \
        Otherwise, the default connection class will be used.
        
        :param      cls         subclass of <XNodeConnection>
        
        :return     <XNodeConnection> || None
        """
        # collect the selected nodes
        nodes = self.selectedNodes()
        if ( len(nodes) != 2 ):
            return None
        
        # create the connection
        con = self.addConnection(cls)
        con.setOutputNode(nodes[0])
        con.setInputNode(nodes[1])
        con.rebuild()
        
        return con