def _is_used_in_graph(var):
 return (not ((var.clients == [('output', 1)]) or (var.clients == [])))

def _is_used_in_graph ( var ) : return ( not ( ( var . clients == [ ( 'output' , 1 ) ] ) or ( var . clients == [ ] ) ) )
returns bool true if var is used by another node in the graph .