code: public static void checkArgumentNotNull(Object reference, String argumentName) {
          if (reference == null) {
              throw ValidatorLogger.LOG.argumentNull(argumentName);
          }
      }
docs: Throws {@link IllegalArgumentException} with an appropriate message if the reference is null.
  
  @param reference the reference to be checked
  @param argumentName name of the argument that is being checked. The name used in the error message.