class Money

def from_subunits(subunits, currency_iso, format: :iso4217)
  currency = Helpers.value_to_currency(currency_iso)
  subunit_to_unit_value = if format == :iso4217
    currency.subunit_to_unit
  elsif format == :stripe
    Helpers::STRIPE_SUBUNIT_OVERRIDE.fetch(currency.iso_code, currency.subunit_to_unit)
  else
    raise ArgumentError, "unknown format #{format}"
  end
  value = Helpers.value_to_decimal(subunits) / subunit_to_unit_value
  new(value, currency)
end