def reload_local_certificate(self) -> Optional[bool]:
        """Reload the SSL certificate used by the REST API.

        :return: ``True`` if a different certificate has been configured through ``restapi.certfile` setting, ``None``
            otherwise.
        """
        if self.__protocol == 'https':
            on_disk_cert_serial_number = self.get_certificate_serial_number()
            if on_disk_cert_serial_number != self.__ssl_serial_number:
                self._received_new_cert = True
                self.__ssl_serial_number = on_disk_cert_serial_number
                return True
Reload the SSL certificate used by the REST API.

        :return: ``True`` if a different certificate has been configured through ``restapi.certfile` setting, ``None``
            otherwise.
        
patroni/api.py