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