public static Level toLevel(String sArg) {
        return (Level) toLevel(sArg, Level.DEBUG);
    }
Convert the string passed as argument to a level. If the conversion fails,
then this method returns {@link #DEBUG}.

@param sArg a string
@return corresponding Level
log4j-over-slf4j/src/main/java/org/apache/log4j/Level.java