The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.

In externally visible method 'IExchangeRatesClient FactoryExtensions.GetExchangeRatesClient(OpenApiClientFactory factory)', validate parameter 'factory' is non-null before using it. If appropriate, throw an 'ArgumentNullException' when the argument is 'null'.

In externally visible method 'OpenApiClientFactoryBuilder FactoryExtensions.AddExchangeRatesClient(OpenApiClientFactoryBuilder builder, ExchangeRatesClientOptions options, Action<HttpClient> configureClient = null, Func<HttpClientHandler> configureHttpMessageHandler = null)', validate parameter 'builder' is non-null before using it. If appropriate, throw an 'ArgumentNullException' when the argument is 'null'.

Unused field 'CURRENCY_LIST_PATTERN'

In virtual/interface member IExchangeRatesClient.ConvertOfficialRates(decimal, string, string, CancellationToken), rename parameter to so that it no longer conflicts with the reserved language keyword 'To'. Using a reserved keyword as the name of a parameter on a virtual/interface member makes it harder for consumers in other languages to override/implement the member.

In virtual/interface member IExchangeRatesClient.GetOfficialRatesByDate(IEnumerable<string>, string, CancellationToken), rename parameter date so that it no longer conflicts with the reserved language keyword 'Date'. Using a reserved keyword as the name of a parameter on a virtual/interface member makes it harder for consumers in other languages to override/implement the member.

In virtual/interface member IExchangeRatesClient.ConvertCommercialRate(decimal, string, string, CancellationToken), rename parameter to so that it no longer conflicts with the reserved language keyword 'To'. Using a reserved keyword as the name of a parameter on a virtual/interface member makes it harder for consumers in other languages to override/implement the member.

Change 'List<CommercialRate>' in 'GetCommercialRatesResponse.CommercialRatesList' to use 'Collection<T>', 'ReadOnlyCollection<T>' or 'KeyedCollection<K,V>'

Change 'CommercialRatesList' to be read-only by removing the property setter

The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.