- loggerName
- the name of the logger to set the level on, which must not be null.
- levelName
- the level to set on the logger, which may be null.
Type Reason Java.Lang.IllegalArgumentException if loggerName is not a registered logger or if levelName is not null and not valid.
Sets the log level of a logger. LevelName set to null means the level is inherited from the nearest non-null ancestor.