title: How should I check if BufferedWriter is already closed?
body: <p>In android, I am writing a file on clicking a button and on clicking next time, it saves the file and closes the buffered writer. But, I also want to implement functionality to close the buffered writer in onDestroy function. Before that I need to know if <code>Bufferedwriter</code> is already closed. How will I check if Buffered Writer is already closed?</p>
  
  <p>In addition to that, does <code>bufferedWriter.close()</code> function set <code>bufferedWriter</code> to <code>null</code>?</p>