code: public static PactDslJsonRootValue hexValue(String hexValue) {
      if (!hexValue.matches(HEXADECIMAL)) {
        throw new InvalidMatcherException(EXAMPLE + hexValue + "\" is not a hexadecimal value");
      }
      PactDslJsonRootValue value = new PactDslJsonRootValue();
      value.setValue(hexValue);
      value.setMatcher(value.regexp("[0-9a-fA-F]+"));
      return value;
    }
docs: Value that must be encoded as a hexadecimal value
  @param hexValue example value to use for generated bodies