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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 role(self):
 """The iperf3 instance role valid roles are 'c'=client and 's'=server :rtype: 'c' or 's' """

        try:
            self._role = c_char(
                self.lib.iperf_get_test_role(self._test)
            ).value.decode('utf-8')
        except TypeError:
            self._role = c_char(
                chr(self.lib.iperf_get_test_role(self._test))
            ).value.decode('utf-8')
        return self._role