LOG_FORMAT_DEFAULT is constant for default output log format of logger (json).

LOG_FORMAT_JSON is constant for output log with json format of logger.

LOG_FORMAT_TEXT is constant for output log with text format of logger.

LOG_LEVEL_DEBUG is constant for debug level of logger.

LOG_LEVEL_DEFAULT is constant for default log level of logger (info).

LOG_LEVEL_ERROR is constant for error level of logger.

LOG_LEVEL_INFO is constant for info level of logger.

LoggingConfig will be used to apply logging config, it also provides utilities.