title: Does JsonReader in gson need to be explicitly closed
body: <p>I want to do this with gson when reading from a json file:</p>
  
  <pre><code>JsonReader reader = new JsonReader(new InputStreamReader(
                  new FileInputStream(filename)));
  JsonParser jsonParser = new JsonParser();
  return jsonParser.parse(reader).getAsJsonObject();
  </code></pre>
  
  <p>I'll do more things with the returned JsonObject somewhere else.</p>
  
  <p>My question is that whether this is okay since I never close the reader.</p>
  
  <p>From the gson API of JsonReader, it shows that JsonReader implements AutoClosable. Does that mean JsonReader will be automatically closed? If so, when is it closed and how? </p>
  
  <p>Thank you.</p>