### Question:
MacAddresses { public static boolean isMacAddress(String in) { return MAC_ADDR_PATTERN.matcher(in).matches(); }  static boolean isMacAddress(String in);  }### Answer:
@Test public void testIsMacAddress() { for (String addr : expectedValidAddresses) assertTrue(isMacAddress(addr)); for (String addr : expectedInvalidAddresses) assertFalse(isMacAddress(addr)); }