### Question:
AckFailureMessageDecoder implements RequestMessageDecoder { @Override public int signature() { return AckFailureMessage.SIGNATURE; } AckFailureMessageDecoder( BoltResponseHandler responseHandler ); @Override int signature(); @Override BoltResponseHandler responseHandler(); @Override RequestMessage decode( Neo4jPack.Unpacker unpacker );  }### Answer:
@Test void shouldReturnCorrectSignature() { assertEquals( AckFailureMessage.SIGNATURE, decoder.signature() ); }