def sign(self, tx=None, wifs=[], reconstruct_tx=True):
    ' Sign a provided transaction with the provided key(s)\n\n            :param dict tx: The transaction to be signed and returned\n            :param string wifs: One or many wif keys to use for signing\n                a transaction. If not present, the keys will be loaded\n                from the wallet as defined in "missing_signatures" key\n                of the transactions.\n            :param bool reconstruct_tx: when set to False and tx\n                is already contructed, it will not reconstructed\n                and already added signatures remain\n\n        '
    if tx:
        txbuffer = TransactionBuilder(tx, crea_instance=self)
    else:
        txbuffer = self.txbuffer
    txbuffer.appendWif(wifs)
    txbuffer.appendMissingSignatures()
    txbuffer.sign(reconstruct_tx=reconstruct_tx)
    return txbuffer.json()
Sign a provided transaction with the provided key(s)

:param dict tx: The transaction to be signed and returned
:param string wifs: One or many wif keys to use for signing
    a transaction. If not present, the keys will be loaded
    from the wallet as defined in "missing_signatures" key
    of the transactions.
:param bool reconstruct_tx: when set to False and tx
    is already contructed, it will not reconstructed
    and already added signatures remain
def sign(self, tx=None, wifs=[], reconstruct_tx=True):
    ' Sign a provided transaction with the provided key(s)\n\n            :param dict tx: The transaction to be signed and returned\n            :param string wifs: One or many wif keys to use for signing\n                a transaction. If not present, the keys will be loaded\n                from the wallet as defined in "missing_signatures" key\n                of the transactions.\n            :param bool reconstruct_tx: when set to False and tx\n                is already contructed, it will not reconstructed\n                and already added signatures remain\n\n        '
    if tx:
        txbuffer = TransactionBuilder(tx, crea_instance=self)
    else:
        txbuffer = self.txbuffer
    txbuffer.appendWif(wifs)
    txbuffer.appendMissingSignatures()
    txbuffer.sign(reconstruct_tx=reconstruct_tx)
    return txbuffer.json()