viewModelScope.launch {
            _stateFlow.update { it.copy(nowCopying = true) }
            withContext(singleThreadContext) {
                val fileSize = sourceUsbFile.length // singleThread
                val outputStream = BufferedOutputStream(targetFile.outputStream()) // IO
                val input = UsbFileStreamFactory.createBufferedInputStream(sourceUsbFile, fs) // singleThread
                val buffer = ByteArray(fs.chunkSize)
                var fullSize = 0L
                var resultSize = input.read(buffer) // singleThread

                var percent = 0
                var newPercent = -1
                while (resultSize != -1) {
                    outputStream.write(buffer) // IO
                    fullSize += resultSize

                    newPercent = ((fullSize.toFloat() / fileSize.toFloat()) * 100).toInt()
                    resultSize = input.read(buffer) // singleThread

                    //println("Was read $fullSize")
                    yield()

                    if (newPercent != percent) {
                        percent = newPercent
                        deviceState = deviceState.copy(bytesWasReadPercent = percent)
                        // TODO report progress
                    }

                }
                outputStream.close() // IO
            }
            println("$sourceUsbFile copied")
            _stateFlow.update { it.copy(nowCopying = false) }
        }