void prepareResponse(final int maxlength, final int messageType) {
            messageContents = new byte[maxlength];
            currentOutputPosition = 0;
            addBytes(SIGNATURE);
            addULong(messageType);
        }
Prepares the object to create a response of the given length.

@param maxlength
           the maximum length of the response to prepare,
           including the type and the signature (which this method
           adds).
httpclient5/src/main/java/org/apache/hc/client5/http/impl/auth/NTLMEngineImpl.java