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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 _error_to_string(self, error_id):
 """Returns an error string from libiperf :param error_id: The error_id produced by libiperf :rtype: string """

        strerror = self.lib.iperf_strerror
        strerror.restype = c_char_p
        return strerror(error_id).decode('utf-8')