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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _ensure_programmer_executable():
 """ Find the lpc21isp executable and ensure it is executable """

    # Find the lpc21isp executable, explicitly allowing the case where it
    # is not executable (since that’s exactly what we’re trying to fix)
    updater_executable = shutil.which('lpc21isp',
                                      mode=os.F_OK)
    # updater_executable might be None; we’re passing it here unchecked
    # because if it is None, we’re about to fail when we try to program
    # the smoothie, and we want the exception to bubble up.
    os.chmod(updater_executable, 0o777)