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