def METHOD_NAME(cls):
    # create test message in file on device
    (status, output) = cls.target.run('echo "%s" >  %s/%s' % 
            (cls.test_msg, cls.test_dir, cls.test_file))
    msg = ('File %s not create test message on %s' % (cls.test_file, cls.device))
    cls.assertEqual(status, 0,  msg = msg)