fun addUtxos(outpoints: List<OutPoint>): TxBuilder

Add the list of outpoints to the internal list of UTXOs that must be spent. If an error occurs while adding any of the UTXOs then none of them are added and the error is returned. These have priority over the "unspendable" utxos, meaning that if a utxo is present both in the "utxos" and the "unspendable" list, it will be spent.