code: public PactDslJsonArray date(String format, Date example) {
          FastDateFormat instance = FastDateFormat.getInstance(format);
          body.put(instance.format(example));
          matchers.addRule(rootPath + appendArrayIndex(0), matchDate(format));
          return this;
      }
docs: Element that must match the provided date format
  @param format date format to match
  @param example example date to use for generated values