ld     }   }    fileprivate mutating func _uniqueStorage() -> _StorageClass {     if !isKnownUniquelyReferenced(&_storage) {       _storage = _StorageClass(copying: _storage)     }     return _storage   }    mutating func decodeMessage<D: SwiftProtobuf.Decoder>(decoder: inout D) throws {     _ = _uniqueStorage()     try withExtendedLifetime(_storage) { (_storage: _StorageClass) in       while let fieldNumber = try decoder.nextFieldNumber() {         switch fieldNumber {         case 0: try decoder.decodeSingularMessageField(value: &_storage._