<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _isbn_cleaner(fn):
 """ Decorator for calling other functions from this module. Purpose of this decorator is to clean the ISBN string from garbage and return list of digits. Args: fn (function):
 function in which will be :func:`_clean_isbn(isbn)` call wrapped. """

    @wraps(fn)
    def wrapper(isbn):
        return fn(_clean_isbn(isbn))

    return wrapper