public byte[] decrypt(final byte[] nonce, ByteBuffer ciphertext) throws GeneralSecurityException {
    ByteBuffer plaintext = ByteBuffer.allocate(ciphertext.remaining());
    process(nonce, plaintext, ciphertext);
    return plaintext.array();
  }
Decrypts {@code ciphertext} using {@code nonce}.
java_src/src/main/java/com/google/crypto/tink/aead/internal/InsecureNonceChaCha20Base.java