import sys
import time
time.sleep(2)
sys.stderr.write("NOK this line\n")
time.sleep(2)
sys.stdout.write("OK this line\n")
time.sleep(2)
sys.stdout.write("OK this line again\n")
time.sleep(2)
sys.stderr.write("NOK this line again\n")
time.sleep(2)
sys.stdout.write("OK this line\n")
time.sleep(2)
sys.stderr.write("NOK this line\n")
time.sleep(2)
sys.stdout.write("OK this line again\n")
time.sleep(2)
sys.stderr.write("NOK this line again\n")