Offline wallet and View only wallet using Monero Wallet RPC.  
I was trying to test this library in a scenario very similar to the one described [here](https://github.com/monero-ecosystem/monero-javascript/blob/master/docs/developer_guide/view_only_offline.md), the main difference is that the view only wallet is using the standard `monero-wallet-rpc` binary.

I exported the outputs hex using the `export_outputs` method and created an unsigned transaction using the `transfer` method, getting in both cases an `hex` of the required data. When trying to use this data in the `MoneroWalletFull` offline wallet I get the following:

```
> await this.wallet.importOutputsHex("<outputs_data_hex>");
0
> await this.wallet.signTxs("<unsigned_txset_hex>");
undefined
```

It is very likely that I'm missing some intermediate step, such as getting the transaction hex from the `unsigned_txset`, however I couldn't find any information about it.

Is there any documentation, guide or example available on how to do this?