readAttributeOpenPeriod(completion:)
Declaration
func readAttributeOpenPeriod(completion: @escaping @Sendable (NSNumber?, (any Error)?) -> Void)func readAttributeOpenPeriod() async throws -> NSNumberfunc readAttributeOpenPeriod(completion: @escaping @Sendable (NSNumber?, (any Error)?) -> Void)func readAttributeOpenPeriod() async throws -> NSNumber