protected String renderLevel(int levelInt) {
        switch (levelInt) {
            case LOG_LEVEL_TRACE:
                return "TRACE";
            case LOG_LEVEL_DEBUG:
                return("DEBUG");
            case LOG_LEVEL_INFO:
                return "INFO";
            case LOG_LEVEL_WARN:
                return "WARN";
            case LOG_LEVEL_ERROR:
                return "ERROR";
        }
        throw new IllegalStateException("Unrecognized level ["+levelInt+"]");
    }
SimpleLogger's implementation of
{@link org.slf4j.helpers.AbstractLogger#handleNormalizedLoggingCall(Level, Marker, String, Object[], Throwable) AbstractLogger#handleNormalizedLoggingCall}
}

@param level the SLF4J level for this event
@param marker  The marker to be used for this event, may be null.
@param messagePattern The message pattern which will be parsed and formatted
@param arguments  the array of arguments to be formatted, may be null
@param throwable  The exception whose stack trace should be logged, may be null
slf4j-simple/src/main/java/org/slf4j/simple/SimpleLogger.java