The reasons for the target error.
|The currency code is invalid and does not follow ISO 4217.
|The currency code is not supported.
|The currency code already exists. When creating an exchange rate, its currency should not be associated with any existing exchange rate. When creating a list of exchange rates, there should not be two exchange rates associated with same currency.
|The exchange rate value is invalid. When the
ExchangeRate.exchangeRate should be larger
than 0. Otherwise it is invalid.
|The exchange rate value is not found. When the
ExchangeRate.exchangeRate should be assigned by Google. It is not found if Google
cannot find such an exchange rate.
|The value returned if the actual value is not exposed by the requested API version.