in src/main/java/org/apache/maven/shared/io/logging/MessageLevels.java [101:107]
public static String getLevelLabel(int messageLevel) {
if (messageLevel > -1 && LEVEL_NAMES.size() > messageLevel) {
return (String) LEVEL_NAMES.get(messageLevel);
}
throw new IllegalArgumentException("Invalid message level: " + messageLevel);
}