1. override
void reassembleApplication()

Called when the ext.flutter.reassemble signal is sent by development tools.

This is used by development tools when the application code has changed, to cause the application to pick up any changed code. Bindings are expected to use this method to reregister anything that uses closures, so that they do not keep pointing to old code, and to flush any caches of previously computed values, in case the new code would compute them differently.

Source 

@override
void reassembleApplication() {
  super.reassembleApplication();
  renderView.reassemble();
  handleBeginFrame(null);
}