New : create a new logger.

NewHandleError : create a new error for the Handler.

NewWithGroup : create a new logger with a group.

LevelFatal : Fatal level.

LevelNames : Map of slog.Leveler to string.

LogLevel is a global variable that can be used to set the log level.

H : custom Handler for log messages.

HandleError : error type for the Handler.

Logger : custom logger.