in lib/facebook_ads/ad_objects/server_side/util.rb [154:166]
def self.normalize_currency(currency)
currency = currency.gsub(/[^a-z]/,'')
iso_currency = Money::Currency.find(currency)
if iso_currency == nil
raise ArgumentError, "Invalid format for currency:'" + currency + "'.Please follow ISO 3-letter ISO 4217 standard for representing currency. Eg: usd"
end
return currency;
end