docs: def split_utxos(self, wif, limit, fee=10000, max_outputs=100):
          """Split utxos of <wif> unitil <limit> or <max_outputs> reached."""
          key = deserialize.key(self.testnet, wif)
          limit = deserialize.positive_integer(limit)
          fee = deserialize.positive_integer(fee)
          max_outputs = deserialize.positive_integer(max_outputs)
          spendables = control.retrieve_utxos(self.service, [key.address()])
          txids = control.split_utxos(self.service, self.testnet, key,
                                      spendables, limit, fee=fee,
                                      max_outputs=max_outputs,
                                      publish=(not self.dryrun))
          return serialize.txids(txids)