### Question:
AckFailureMessageDecoder implements RequestMessageDecoder { @Override public RequestMessage decode( Neo4jPack.Unpacker unpacker ) throws IOException { return AckFailureMessage.INSTANCE; } AckFailureMessageDecoder( BoltResponseHandler responseHandler ); @Override int signature(); @Override BoltResponseHandler responseHandler(); @Override RequestMessage decode( Neo4jPack.Unpacker unpacker );  }### Answer:
@Test void shouldDecodeAckFailure() throws Exception { assertEquals( AckFailureMessage.INSTANCE, decoder.decode( mock( Unpacker.class ) ) ); }