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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def refill(self, from_address, to_address, nfees, ntokens, password, min_confirmations=6, sync=False):
 """ Refill wallets with the necessary fuel to perform spool transactions Args: from_address (Tuple[str]):
 Federation wallet address. Fuels the wallets with tokens and fees. All transactions to wallets holding a particular piece should come from the Federation wallet to_address (str):
 Wallet address that needs to perform a spool transaction nfees (int):
 Number of fees to transfer. Each fee is 10000 satoshi. Used to pay for the transactions ntokens (int):
 Number of tokens to transfer. Each token is 600 satoshi. Used to register hashes in the blockchain password (str):
 Password for the Federation wallet. Used to sign the transaction min_confirmations (int):
 Number of confirmations when chosing the inputs of the transaction. Defaults to 6 sync (bool):
 Perform the transaction in synchronous mode, the call to the function will block until there is at least on confirmation on the blockchain. Defaults to False Returns: str: transaction id """

        path, from_address = from_address
        verb = Spoolverb()
        # nfees + 1: nfees to refill plus one fee for the refill transaction itself
        inputs = self.select_inputs(from_address, nfees + 1, ntokens, min_confirmations=min_confirmations)
        outputs = [{'address': to_address, 'value': self.token}] * ntokens
        outputs += [{'address': to_address, 'value': self.fee}] * nfees
        outputs += [{'script': self._t._op_return_hex(verb.fuel), 'value': 0}]
        unsigned_tx = self._t.build_transaction(inputs, outputs)
        signed_tx = self._t.sign_transaction(unsigned_tx, password, path=path)
        txid = self._t.push(signed_tx)
        return txid