docs: public void setDatePatternLocale(String datePatternLocale) {
  		if (datePatternLocale == null) {
  			LogLog.warn("Null date pattern locale supplied for appender [" + this.getName() + "], defaulting to " + this.getProperties().getDatePatternLocale());
  			return;
  		}
  		datePatternLocale = datePatternLocale.trim();
  		if ("".equals(datePatternLocale)) {
  			LogLog.warn("Empty date pattern locale supplied for appender [" + this.getName() + "], defaulting to " + this.getProperties().getDatePatternLocale());
  			return;
  		}
  		final String[] parts = datePatternLocale.split("_");
  		switch (parts.length) {
  		case 1:
  			this.getProperties().setDatePatternLocale(new Locale(parts[0]));
  			break;
  		case 2:
  			this.getProperties().setDatePatternLocale(new Locale(parts[0], parts[1]));
  			break;
  		default:
  			LogLog.warn("Unable to parse date pattern locale supplied for appender [" + this.getName() + "], defaulting to " + this.getProperties().getDatePatternLocale());
  		}
  	}