def get_current_btc(self, time: datetime = None) -> Decimal:
        """
        Get how much btc this investment is currently worth.
        :param time: the time you want data regarding. Cant ever be after closed_date
        :return: current worth in btc
        """
        time, cache_time_name = _default_time_and_cache_name(self._default_time(time))

        def inner_method():
            fraction = self.get_fraction(time=time)
            if fraction != 0:
                return fraction * \
                       GlobalBalance.objects.get_btc_by_time(time=time)
            return Decimal(0)

        return get_and_or_set_cache(f"investment_{self.pk}_{cache_time_name}_current_btc",
                                    inner_method,
                                    60 * 5)










def get_and_or_set_cache(key: str, setterMethod: FunctionType, timeout: int = None) -> Any:
    """
    Method for getting the content of the cache and if it's empty setting it, so it's use-able for the next request.
    :param key: the key of value in the cache
    :param setterMethod: method used to set the cache value if the cache is invalid
    :param timeout: how long the cache is valid - none if forever
    :return: the value of the cache or the setterMethod if the cache is invalid
    """
    output = cache.get(key)
    if not output:
        output = setterMethod()
        cache.set(key, output, timeout)

    return output