This function is only called when sender is closed forcefully. It will fail all the
        incomplete batches and return.

def abort_incomplete_batches(self):
        """
        This function is only called when sender is closed forcefully. It will fail all the
        incomplete batches and return.
        """
        # We need to keep aborting the incomplete batch until no thread is trying to append to
        # 1. Avoid losing batches.
        # 2. Free up memory in case appending threads are blocked on buffer full.
        # This is a tight loop but should be able to get through very quickly.
        while True:
            self._abort_batches()
            if not self._appends_in_progress.get():
                break
        # After this point, no thread will append any messages because they will see the close
        # flag set. We need to do the last abort after no thread was appending in case the there was a new
        # batch appended by the last appending thread.
        self._abort_batches()
        self._batches.clear()