def METHOD_NAME(self):
    """test ev_written event"""
    task = task_self()
    eh = TestHandler()
    worker = task.shell("cat", handler=eh)
    content = "abcdefghijklmnopqrstuvwxyz\n"
    worker.write(content)
    worker.set_write_eof()
    task.resume()
    eh.do_asserts_read_write_notimeout()
    self.assertEqual(eh.cnt_written, 1)
    self.assertEqual(eh.bytes_written, len(content))