code: public byte [] box(byte [] message, byte [] theNonce) {
              if (message==null) return null;
              return box(message, 0, message.length, theNonce);
          }
docs: /*
  @description
  Encrypt and authenticates message using peer's public key,
  our secret key, and the given nonce, which must be unique
  for each distinct message for a key pair.
  
  Explicitly pass the nonce
  
  Returns an encrypted and authenticated message,
  which is nacl.box.overheadLength longer than the original message.