### Question:
JidUtil { public static boolean equals(Jid jidOne, Jid jidTwo) { if (jidOne != null) { return jidOne.equals(jidTwo); } return jidTwo == null; }  static boolean isTypicalValidEntityBareJid(CharSequence jid); static EntityBareJid validateTypicalEntityBareJid(CharSequence jidcs); static boolean isValidEntityBareJid(CharSequence jid); static EntityBareJid validateEntityBareJid(CharSequence jidcs); static void filterEntityBareJid(Collection<? extends Jid> in, Collection<? super EntityBareJid> out); static Set<EntityBareJid> filterEntityBareJidSet(Collection<? extends Jid> input); static List<EntityBareJid> filterEntityBareJidList(Collection<? extends Jid> input); static void filterEntityFullJid(Collection<? extends Jid> in, Collection<? super EntityFullJid> out); static Set<EntityFullJid> filterEntityFullJidSet(Collection<? extends Jid> input); static List<EntityFullJid> filterEntityFullJidList(Collection<? extends Jid> input); static void filterDomainFullJid(Collection<? extends Jid> in, Collection<? super DomainFullJid> out); static Set<DomainFullJid> filterDomainFullJidSet(Collection<? extends Jid> input); static List<DomainFullJid> filterDomainFullJidList(Collection<? extends Jid> input); static Set<EntityBareJid> entityBareJidSetFrom(Collection<? extends CharSequence> jidStrings); static void entityBareJidsFrom(Collection<? extends CharSequence> jidStrings, Collection<? super EntityBareJid> output,
			List<XmppStringprepException> exceptions); static Set<Jid> jidSetFrom(String[] jids); static Set<Jid> jidSetFrom(Collection<? extends CharSequence> jidStrings); static void jidsFrom(Collection<? extends CharSequence> jidStrings, Collection<? super Jid> output,
			List<XmppStringprepException> exceptions); static List<String> toStringList(Collection<? extends Jid> jids); static Set<String> toStringSet(Collection<? extends Jid> jids); static void toStrings(Collection<? extends Jid> jids, Collection<? super String> jidStrings); static boolean equals(Jid jidOne, Jid jidTwo);  }### Answer:
@Test public void testEquals() { assertTrue(JidUtil.equals(null, null)); assertFalse(JidUtil.equals(null, JidTestUtil.BARE_JID_1)); assertFalse(JidUtil.equals(JidTestUtil.BARE_JID_1, null)); assertTrue(JidUtil.equals(JidTestUtil.BARE_JID_1, JidTestUtil.BARE_JID_1)); assertFalse(JidUtil.equals(JidTestUtil.BARE_JID_1, JidTestUtil.BARE_JID_2)); }