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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 close(self):
 """Closes the HTTP connection to the RPC server."""

        if self.connection is not None:
            logger.debug("Closing connection to %s:%s", self.url.hostname, self.url.port)
            try:
                self.connection.close()
            except httplib.HTTPException:
                logger.warning("Error while closing connection", exc_info=True)
            self.connection = None