### Question:
Utils { public static String normalizeUuid(String string) { return string.replaceFirst("([0-9a-fA-F]{8})([0-9a-fA-F]{4})([0-9a-fA-F]{4})([0-9a-fA-F]{4})([0-9a-fA-F]+)", "$1-$2-$3-$4-$5"); } private  Utils(); static IpPrefix createIpPrefix(String cidr); static IpAddress createIpAddress(String ipAddress); static String getStringIpPrefix(IpPrefix ipPrefix); static String getStringIpAddress(IpAddress ipAddress); static String normalizeUuid(String string); static void syncNat(ReadWriteTransaction rwTx, Floatingip oldFloatingIp, Floatingip newFloatingIp); static void removeNat(ReadWriteTransaction rwTx, Floatingip removedFloatingIp);  }### Answer:
@Test public final void testNormalizeUuid_lowercaseUuid() { assertEquals("01234567-abcd-ef01-0123-0123456789ab", Utils.normalizeUuid("01234567-abcd-ef01-0123-0123456789ab")); }
@Test public final void testNormalizeUuid_uppercaseUuid() { assertEquals("01234567-ABCD-EF01-0123-0123456789AB", Utils.normalizeUuid("01234567-ABCD-EF01-0123-0123456789AB")); }
@Test public final void testNormalizeUuid_mixUuid() { assertEquals("01234567-ABCD-ef01-0123-0123456789Ab", Utils.normalizeUuid("01234567-ABCD-ef01-0123-0123456789Ab")); }
@Test public final void testNormalizeUuid_noSlashLowercaseUuid() { assertEquals("01234567-abcd-ef01-0123-0123456789ab", Utils.normalizeUuid("01234567abcdef0101230123456789ab")); }
@Test public final void testNormalizeUuid_noSlashUppercaseUuid() { assertEquals("01234567-ABCD-EF01-0123-0123456789AB", Utils.normalizeUuid("01234567ABCDEF0101230123456789AB")); }
@Test public final void testNormalizeUuid_noSlashMixUuid() { assertEquals("01234567-ABCD-ef01-0123-0123456789Ab", Utils.normalizeUuid("01234567ABCDef0101230123456789Ab")); }
@Test public final void testNormalizeUuid_emptyUuid() { assertEquals("", Utils.normalizeUuid("")); }
@Test public final void testNormalizeUuid_badUuid() { assertEquals("abcdxy", Utils.normalizeUuid("abcdxy")); }
@Test public final void testNormalizeUuid_nullUuid() { thrown.expect(NullPointerException.class); Utils.normalizeUuid(null); }