How to use the mirakuru.SimpleExecutor function in mirakuru

def test_daemons_killing():
    """
    Test if all subprocesses of SimpleExecutor can be killed.

    The most problematic subprocesses are daemons or other services that
    change the process group ID. This test verifies that daemon process
    is killed after executor's kill().
    """
    executor = SimpleExecutor(('python', SAMPLE_DAEMON_PATH), shell=True)
    executor.start()
    time.sleep(2)
    assert executor.running() is not True, \
        "Executor should not have subprocess running as it started a daemon."

    assert SAMPLE_DAEMON_PATH in ps_aux()
    executor.kill()
    assert SAMPLE_DAEMON_PATH not in ps_aux()

def test_already_closed():
    """Check that the executor cleans after itself after it exited earlier."""
    with SimpleExecutor('python') as executor:
        assert executor.running()
        os.killpg(executor.process.pid, SIGKILL)

        def process_stopped():
            """Return True only only when self.process is not running."""
            return executor.running() is False
        executor.wait_for(process_stopped)
        assert executor.process
    assert not executor.process

def test_custom_signal_kill():
    """Start process and shuts it down using signal SIGQUIT."""
    executor = SimpleExecutor(SLEEP_300, sig_kill=signal.SIGQUIT)
    executor.start()
    assert executor.running() is True
    executor.kill()
    assert executor.running() is False

def test_kill_custom_signal_kill():
    """Start process and shuts it down using signal SIGQUIT passed to kill."""
    executor = SimpleExecutor(SLEEP_300)
    executor.start()
    assert executor.running() is True
    executor.kill(sig=signal.SIGQUIT)
    assert executor.running() is False

We ignore and skip OsError indicates there's no such process.
    """
    # pylint: disable=protected-access, missing-docstring
    def raise_os_error(*_, **__):

        os_error = OSError()
        os_error.errno = errno.ESRCH
        raise os_error

    def processes_with_env_mock(*_, **__):
        return [1]

    with patch(
            'mirakuru.base.processes_with_env', new=processes_with_env_mock
    ), patch('os.kill', new=raise_os_error):
        executor = SimpleExecutor(SLEEP_300)
        executor._kill_all_kids(executor._sig_stop)