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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 params(self):
 """ Parsed query string. """

        if self._params is None:
            self._params = self.arg_container()

            data = compat.parse_qs(self.environ('QUERY_STRING') or '')
            for k, v in data.items():
                self._params[k] = v[0]

        return self._params