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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 cli():
 """Migrate data to S3. Use the `copy` subcommand to copy data to S3. This can be done safely while Indico is running. At the end it will show you what you need to add to your `indico.conf`. Once you updated your config with the new storage backends, you can use the `apply` subcommand to update your database so files will actually be loaded using the new S3 storage backends. In case you ever need to switch back to your previous storage, you can use `revert` to undo the database changes. """

    if config.DB_LOG:
        click.secho('Warning: The database logger is currently enabled (DB_LOG = True).\n'
                    'This will slow down the migration. Unless you database is very small, please disable it.',
                    fg='yellow')
        click.confirm('Continue anyway?', abort=True)