Converts a given number of satoshi to another currency as a formatted
    string rounded down to the proper number of decimal places. Results are
    cached using a decorator for 60 seconds by default. See :ref:`cache times`.

    :param num: The number of satoshi.
    :type num: ``int``
    :param currency: One of the :ref:`supported currencies`.
    :type currency: ``str``
    :rtype: ``str``

def satoshi_to_currency_cached(num, currency):
    """Converts a given number of satoshi to another currency as a formatted
    string rounded down to the proper number of decimal places. Results are
    cached using a decorator for 60 seconds by default. See :ref:`cache times`.

    :param num: The number of satoshi.
    :type num: ``int``
    :param currency: One of the :ref:`supported currencies`.
    :type currency: ``str``
    :rtype: ``str``
    """
    return '{:f}'.format(
        Decimal(
            num / Decimal(currency_to_satoshi_cached(1, currency))
        ).quantize(
            Decimal('0.' + '0' * CURRENCY_PRECISION[currency]),
            rounding=ROUND_DOWN
        ).normalize()
    )