https://travis-ci.org/github/bitcoin/bitcoin/jobs/680452476#L6107
view.AccessCoin(txin.prevout); 
        }
        view.SetBackend(viewDummy); 
    }
    
    for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) {
        PSBTInput& input = psbtx.inputs.at(i);
        if (input.non_witness_utxo || !input.witness_utxo.IsNull()) {
            continue;
        }
        const Coin& coin = view.AccessCoin(psbtx.tx->vin[i].prevout);
        if (IsSegWitOutput(provider, coin.out.scriptPubKey)) {
            input.witness_utxo = coin.out;
        }
        
        
        
        SignPSBTInput(public_provider, psbtx, i,  1);
    }
    
    for (unsigned int i = 0; i < psbtx.tx->vout.size(); ++i) {
        UpdatePSBTOutput(public_provider, psbtx, i);
    }
    CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
    ssTx << psbtx;
    return EncodeBase64(MakeUCharSpan(ssTx));
},
    };
}
static RPCHelpMan joinpsbts()