### Question:
SerializerRegistryImpl implements SerializerRegistry { @Override public <K> boolean unregisterSerializer(MessageTypeKey<K> msgTypeKey) { if (msgTypeKey == null) { throw new IllegalArgumentException("MessageTypeKey is null"); } OFGeneralSerializer serializer = registry.remove(msgTypeKey); if (serializer == null) { return false; } return true; }  @Override void init(); @Override @SuppressWarnings("unchecked") S getSerializer(MessageTypeKey<K> msgTypeKey); @Override void registerSerializer(MessageTypeKey<K> msgTypeKey, OFGeneralSerializer serializer); @Override boolean unregisterSerializer(MessageTypeKey<K> msgTypeKey);  }### Answer:
@Test public void testUnRegisterSerializer(){ SerializerRegistryImpl serReg = new SerializerRegistryImpl(); serReg.init(); serReg.registerSerializer(new MessageTypeKey<>(OF13, Match.class), new OF13MatchSerializer()); Assert.assertTrue("Wrong - unregister serializer",serReg.unregisterSerializer(new MessageTypeKey<>(OF13, Match.class))); serReg.registerSerializer(new MessageTypeKey<>(OF13, Match.class), new OF13MatchSerializer()); Assert.assertFalse("Wrong - unregister serializer",serReg.unregisterSerializer(new MessageTypeKey<>(OF10, Match.class))); }