@Test
public void testParseRepeatablePeriodOnly() {

    String isoString = "R/PT1M";
    long[] parsedRepeatable = DateTimeUtils.parseRepeatableDateTime(isoString);
    assertEquals(-1L, parsedRepeatable[0]);
    assertTrue("Parsed delay is bigger than " + MINUTE_IN_MILLISECONDS, parsedRepeatable[1] <= MINUTE_IN_MILLISECONDS);
    assertTrue("Parsed delay is too low! Expected value is between " + MINUTE_IN_MILLISECONDS + " and " + FIFTY_NINE_SECONDS_IN_MILLISECONDS + " but is " + parsedRepeatable[1], parsedRepeatable[1] > FIFTY_NINE_SECONDS_IN_MILLISECONDS);
    assertEquals("Parsed period should be one minute in milliseconds but is " + parsedRepeatable[2], MINUTE_IN_MILLISECONDS, parsedRepeatable[2]);
}