def test_stdouterrin_setnull():

->     cap = py.io.StdCaptureFD()

       from py.__.execnet.register import stdouterrin_setnull

       stdouterrin_setnull()

       import os

       os.write(1, "hello")

       if os.name == "nt":

           os.write(2, "world")

       os.read(0, 1)

       out, err = cap.reset()

       assert not out

       assert not err