Split utxos of <wif> unitil <limit> or <max_outputs> reached.

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)