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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 _parse_protocol_psutil(self, conn):
 """ Returns a string describing the protocol for the given connection in the form `tcp4`, 'udp4` as in `self.cx_state_gauge` """

        protocol = self.PSUTIL_TYPE_MAPPING.get(conn.type, '')
        family = self.PSUTIL_FAMILY_MAPPING.get(conn.family, '')
        return '{}{}'.format(protocol, family)