check
Check with the network whether the passed spendables still exist and are unspent, reserving any that do not so that this wallet will not try to spend them. This function BLOCKS on a network round trip, so it must NOT be called with dataLock held -- in particular never from inside a forEachUtxo or forEachTxo callback.
Check every UTXO in this wallet against the network, reserving any that the network reports as spent or nonexistent so that this wallet will not try to spend it.