code: public static String checkNotBlank(String argument) {
      Objects.requireNonNull(argument, ARG_NOT_BLANK_MSG);
      if (StringUtils.isBlank(argument)) {
        throw new IllegalArgumentException(ARG_NOT_BLANK_MSG);
      }
      return argument;
    }
docs: Checks that a string is both non-null and non-empty.
  
  @see #checkNotBlank(String, String, Object...)