private static String getResourceStringOrMessage(ResourceBundle bundle, String msg) {
        if (bundle == null || msg == null)
            return msg;
        // ResourceBundle::getString throws:
        //
        // * NullPointerException for null keys
        // * ClassCastException if the message is no string
        // * MissingResourceException if there is no message for the key
        //
        // Handle all of these cases here to avoid log-related exceptions from crashing the JVM.
        try {
            return bundle.getString(msg);
        } catch (MissingResourceException ex) {
            return msg;
        } catch (ClassCastException ex) {
            return bundle.getObject(msg).toString();
        }
    }
<p>Level.OFF and Level.ALL levels are not supposed to be used when calling log printing methods.
</p>

<p>We compensate for such incorrect usage by transforming Level.OFF as Level.ERROR and
Level.ALL as Level.TRACE.
</p>

@param jplLevel
@return
slf4j-jdk-platform-logging/src/main/java/org/slf4j/jdk/platform/logging/SLF4JPlatformLogger.java