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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 clear_repository_helper(reserve_fn, clear_fn, retry=5, reservation=None):
 """Helper function to start repository erasure and wait until finish. This helper is used by clear_sel and clear_sdr_repository. """


    if reservation is None:
        reservation = reserve_fn()

    # start erasure
    reservation = _clear_repository(reserve_fn, clear_fn,
                                    INITIATE_ERASE, retry, reservation)

    # give some time to clear
    time.sleep(0.5)

    # wait until finish
    reservation = _clear_repository(reserve_fn, clear_fn,
                                    GET_ERASE_STATUS, retry, reservation)