VideoSubscriberAccount tvOS 12.4 to 13.0 API Differences

VideoSubscriberAccountDefines.h

Added #def VS_INTERNAL_EXPORT

Added #def VS_INTERNAL_EXTERN

VideoSubscriberAccountErrors.h

Added VSErrorCodeRejected

VSAccountManager.h

Added VSOpenTVProviderSettingsURLString

VSAccountMetadataRequest.h

Added VSAccountMetadataRequest.accountProviderAuthenticationToken

VSAccountProviderResponse.h

Added VSAccountProviderAuthenticationSchemeAPI