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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 connection(self):
 """Return an SqlAlchemy connection."""

        if not self._connection:
            logger.debug('Opening connection to: {}'.format(self.dsn))
            self._connection = self.engine.connect()
            logger.debug('Opened connection to: {}'.format(self.dsn))

        # logger.debug("Opening connection to: {}".format(self.dsn))
        return self._connection