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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 fetch_data(self, **var):
 """Retrieve data from CDMRemote for one or more variables."""

        varstr = ','.join(name + self._convert_indices(ind)
                          for name, ind in var.items())
        query = self.query().add_query_parameter(req='data', var=varstr)
        return self._fetch(query)