public IntentIntegrator setRequestCode(int requestCode) {
        if (requestCode <= 0 || requestCode > 0x0000ffff) {
            throw new IllegalArgumentException("requestCode out of range");
        }
        this.requestCode = requestCode;
        return this;
    }
Change the request code that is used for the Intent. If it is changed, it is the caller's
responsibility to check the request code from the result intent.

@param requestCode the new request code
@return this
zxing-android-embedded/src/com/google/zxing/integration/android/IntentIntegrator.java