code: private static Level calculateMinimumLevel(final Level globalLevel, final Map<String, Level> customLevels) {
  		Level minimumLevel = globalLevel;
  		for (Level level : customLevels.values()) {
  			if (level.ordinal() < minimumLevel.ordinal()) {
  				minimumLevel = level;
  			}
  		}
  		return minimumLevel;
  	}
docs: Calculates the minimum severity level that can output any log entries.
  
  @param globalLevel
  Global severity level
  @param customLevels
  Custom severity levels for packages and classes
  @return Minimum severity level