@staticmethod
def _parse_stake(stake):
    """ Stake cane be provided as string and dictionary. Unified here.
        """
    if isinstance(stake, str) and ' ' in stake:
        amount, symbol = stake.split(' ')
        return dict(amount=float(amount), symbol=symbol)
    if isinstance(stake, dict) and 'amount' in stake and 'symbol' in stake:
        return dict(amount=float(stake['amount']), symbol=stake['symbol'])
    raise ValueError('Invalid stake format')
