code: public final Transaction makeTransaction(byte[] payloadBytes, int offset) throws ProtocolException {
          return makeTransaction(payloadBytes, offset, payloadBytes.length, null);
      }
docs: Make a transaction from the payload. Extension point for alternative
  serialization format support.
  
  @throws UnsupportedOperationException if this serializer/deserializer
  does not support deserialization. This can occur either because it's a dummy
  serializer (i.e. for messages with no network parameters), or because
  it does not support deserializing transactions.