and wouldn't takes utxos? the do the coin required to selection required a coin method be to why is what in trait have that nostr:nprofile1qyg8wumn8ghj7mtfwdekkete9e5k7qg3waehxw309ahx7um5wf5kctnrv9ksqg9kd0ncm2yej92y5pwr52mrmgw3tmh736dphd4yx60cv95xt0tt0syftymw optional? that what up selection algorithm is BDK decide