int totalLen;
        if (ctxOffsetFromHeader != null && ctxBytes != null) {
            totalLen = Math.max(SMB2_HEADER_LENGTH + body.length, ctxOffsetFromHeader + ctxBytes.length);
        } else {
            totalLen = SMB2_HEADER_LENGTH + body.length;
        }
        byte[] packet = new byte[totalLen];
        System.arraycopy(header, 0, packet, 0, header.length);

            testMessage.setBytesWritten(10);
            testMessage.chain(second);

            byte[] buffer = new byte[1024];
            int totalLen = testMessage.encode(buffer, 0);

            assertTrue(totalLen > testMessage.getLength());

            // Check next command offset was written
            int nextOffset = SMBUtil.readInt4(buffer, 20);
            assertTrue(nextOffset > 0);