@classmethod
def from_tuple(cls, wallet_tuple: Tuple[('Exchange', 'Instrument', float)]):
    (exchange, instrument, balance) = wallet_tuple
    return cls(exchange, Quantity(instrument, balance))
@classmethod
def from_tuple(cls, wallet_tuple: Tuple[('Exchange', 'Instrument', float)]):
    (exchange, instrument, balance) = wallet_tuple
    return cls(exchange, Quantity(instrument, balance))