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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def remove(self, delete=True):
 """Unregister and optionally delete associated config Options: delete - remove all elements of this VM from the system Return the IMedia from unregistered VM """

        if self.state >= library.MachineState.running:
            session = virtualbox.Session()
            self.lock_machine(session, library.LockType.shared)
            try:
                progress = session.console.power_down()
                progress.wait_for_completion(-1)
            except Exception:
                print("Error powering off machine", file=sys.stderr)
            session.unlock_machine()
            time.sleep(0.5)  # TODO figure out how to ensure session is really unlocked...

        settings_dir = os.path.dirname(self.settings_file_path)
        if delete:
            option = library.CleanupMode.detach_all_return_hard_disks_only
        else:
            option = library.CleanupMode.detach_all_return_none
        media = self.unregister(option)
        if delete:
            progress = self.delete_config(media)
            progress.wait_for_completion(-1)
            media = []

        # if delete - At some point in time virtualbox didn't do a full cleanup
        #             of this dir. Let's double check it has been cleaned up.
        if delete and os.path.exists(settings_dir):
            shutil.rmtree(settings_dir)

        return media