docs: def format_currency(number, currency, format, locale=babel.numbers.LC_NUMERIC,
                      force_frac=None, format_type='standard'):
      """Same as ``babel.numbers.format_currency``, but has ``force_frac``
      argument instead of ``currency_digits``.
  
      If the ``force_frac`` argument is given, the argument is passed down to
      ``pattern.apply``.
      """
      locale = babel.core.Locale.parse(locale)
      if format:
          pattern = babel.numbers.parse_pattern(format)
      else:
          try:
              pattern = locale.currency_formats[format_type]
          except KeyError:
              raise babel.numbers.UnknownCurrencyFormatError(
                  "%r is not a known currency format type" % format_type)
      if force_frac is None:
          fractions = babel.core.get_global('currency_fractions')
          try:
              digits = fractions[currency][0]
          except KeyError:
              digits = fractions['DEFAULT'][0]
          frac = (digits, digits)
      else:
          frac = force_frac
      return pattern.apply(number, locale, currency=currency, force_frac=frac)