code: public static PactDslJsonRootValue stringMatcher(String regex, String value) {
      if (!value.matches(regex)) {
        throw new InvalidMatcherException(EXAMPLE + value + "\" does not match regular expression \"" +
          regex + "\"");
      }
      PactDslJsonRootValue rootValue = new PactDslJsonRootValue();
      rootValue.setValue(value);
      rootValue.setMatcher(new RegexMatcher(regex, value));
      return rootValue;
    }
docs: Value that must match the regular expression
  @param regex regular expression
  @param value example value to use for generated bodies