### Question:
NotificationHelper { public static String addrParams(String attribute, Collection<Address> addrs) { if (addrs == null || addrs.isEmpty()) { return ""; } String[] params = new String[addrs.size()]; int index = 0; Iterator<Address> it = addrs.iterator(); while (it.hasNext()) { params[index++] = addrParam(attribute, it.next()); } return multiParams(params); }  static String multiParams(String... params); static String multiParams(Collection<String> params); static String addrParam(String attribute, Address addr); static String addrParams(String attribute, Collection<Address> addrs); static String addrParam(String attribute, String addr); static String addrParamsAsStrings(String attribute, Collection<String> addrs);  }### Answer:
@Test public void testMultipleAddresses() { String expected = "[{" + PERSON_ADDR_1.getRepresentation() + "}." + ATTR + ",{" + PERSON_ADDR_2.getRepresentation() + "}." + ATTR + ",{" + PERSON_ADDR_3.getRepresentation() + "}." + ATTR + ",{" + PERSON_ADDR_4.getRepresentation() + "}." + ATTR + "]"; List<Address> addrs = ImmutableList.of(PERSON_ADDR_1, PERSON_ADDR_2, PERSON_ADDR_3, PERSON_ADDR_4); String actual = NotificationHelper.addrParams(ATTR, addrs); System.out.println(actual); Assert.assertEquals(expected, actual); }