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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 sql(self, stmt, parameters=None, bulk_parameters=None):
 """ Execute SQL stmt against the crate server. """

        if stmt is None:
            return None

        data = _create_sql_payload(stmt, parameters, bulk_parameters)
        logger.debug(
            'Sending request to %s with payload: %s', self.path, data)
        content = self._json_request('POST', self.path, data=data)
        logger.debug("JSON response for stmt(%s): %s", stmt, content)

        return content