void appendToBuf(byte[] input, int inputOffset, int inputLen) {
        ArrayUtils.checkOffsetAndCount(input.length, inputOffset, inputLen);
        if (buf == null) {
            buf = new ExposedByteArrayOutputStream(inputLen);
        }
        buf.write(input, inputOffset, inputLen);
        this.bufCount += inputLen;
    }
Returns whether reusing nonces is allowed (aka, whether this is nonce misuse-resistant).
Most AEAD ciphers are not, but some are specially constructed so that reusing a key/nonce
pair is safe.
common/src/main/java/org/conscrypt/OpenSSLAeadCipher.java