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