code: public static PactDslJsonRootValue timestamp(String format, Date example) {
      FastDateFormat instance = FastDateFormat.getInstance(format);
      PactDslJsonRootValue value = new PactDslJsonRootValue();
      value.setValue(instance.format(example));
      value.setMatcher(value.matchTimestamp(format));
      return value;
    }
docs: Value that must match the given timestamp format
  @param format timestamp format
  @param example example date and time to use for generated bodies