code: public PactDslJsonArray hexValue(String hexValue) {
          if (!hexValue.matches(HEXADECIMAL)) {
              throw new InvalidMatcherException(EXAMPLE + hexValue + "\" is not a hexadecimal value");
          }
          body.put(hexValue);
          matchers.addRule(rootPath + appendArrayIndex(0), regexp("[0-9a-fA-F]+"));
          return this;
      }
docs: Element that must be encoded as a hexadecimal value
  @param hexValue example value to use for generated bodies