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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_access(self, white_list=None):
 """ clear all ace entries of the share :param white_list: list of username whose access entry won't be cleared :return: sid list of ace entries removed successfully """

        access_entries = self.get_ace_list()
        sid_list = access_entries.sid_list

        if white_list:
            sid_white_list = [UnityAclUser.get_sid(self._cli,
                                                   user,
                                                   self.cifs_server.domain)
                              for user in white_list]
            sid_list = list(set(sid_list) - set(sid_white_list))

        resp = self.delete_ace(sid=sid_list)
        resp.raise_if_err()
        return sid_list