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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 authorization_error_class(response):
 """Return an exception instance that maps to the OAuth Error. :param response: The HTTP response containing a www-authenticate error. """

    message = response.headers.get("www-authenticate")
    if message:
        error = message.replace('"', "").rsplit("=", 1)[1]
    else:
        error = response.status_code
    return _auth_error_mapping[error](response)