docs: public static Integer getInteger(String propertyName, String envName, Integer defaultValue) {
  		checkEnvName(envName);
  		Integer propertyValue = NumberUtil.toIntObject(System.getProperty(propertyName), null);
  		if (propertyValue != null) {
  			return propertyValue;
  		} else {
  			propertyValue = NumberUtil.toIntObject(System.getenv(envName), null);
  			return propertyValue != null ? propertyValue : defaultValue;
  		}
  	}