title: Flutter - Will BLoC stream instances cause memory leak when a widget is closed?
body: <p>There are some scenarios where screens with their respective BLoCs are frequently created and closed. So I'm somewhat concerned about memory safety of the Streams instances created in this process, because it doesn't seem they are disposed somewhere or whether they are GC-ed. This clearly depends on the specific implementation of DART libraries and flutter. So if you know about their behavior, please let me know.</p>
  
  <p>These are some scenarios I have encountered.</p>
  
  <ol>
  <li>Multi-tab browser-like application.</li>
  <li>Navigation through screens. (But it's not that harmful.)</li>
  <li>showDialog() senarios when there are BLoCs inside the dialog. This is a far more common senario. There could be a lot of dialog popping up frequently in an app.</li>
  </ol>
  
  <p>I wonder if it is necessary to override dispose() function and explicitly close all streams in BLoCProvider. It seems existing tutorials didn't mention it.</p>