pause method
void
pause()
Implementation
void pause() {
if (_downloadingStream != null) {
_downloadingStream!.pause();
if (_finalTask != null) {
_finalTask!.state = TaskState.paused;
_streamController.add(_finalTask!);
} else {
_streamController
.add(ProcessTask(processed: 0, total: 0, state: TaskState.paused));
}
}
}