@Override
        protected DocumentReply doDecode(DocumentDeserializer buf) {
            RemoveDocumentReply reply = new RemoveDocumentReply();
            byte flag = buf.getByte(null);
            reply.setWasFound(flag != 0);
            reply.setHighestModificationTimestamp(buf.getLong(null));
            return reply;
        }
This method decodes a reply from the given byte buffer. You are guaranteed to only receive byte buffers
generated by a previous call to {@link #doEncode(DocumentReply, com.yahoo.document.serialization.DocumentSerializer)}.

<p>
This method is NOT exception safe. Return null to signal failure.

@param buf The byte buffer to read from.
@return The decoded reply.
documentapi/src/main/java/com/yahoo/documentapi/messagebus/protocol/RoutableFactories60.java