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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 config(ctx):
 """Show access token and other configuration settings. The access token and command verbosity level can be set on the command line, as environment variables, and in mapbox.ini config files. """

    ctx.default_map = ctx.obj['cfg']
    click.echo("CLI:")
    click.echo("access-token = {0}".format(ctx.obj['access_token']))
    click.echo("verbosity = {0}".format(ctx.obj['verbosity']))
    click.echo("")

    click.echo("Environment:")
    if 'MAPBOX_ACCESS_TOKEN' in os.environ:
        click.echo("MAPBOX_ACCESS_TOKEN = {0}".format(
            os.environ['MAPBOX_ACCESS_TOKEN']))
    if 'MapboxAccessToken' in os.environ:
        click.echo("MapboxAccessToken = {0}".format(
            os.environ['MapboxAccessToken']))
    if 'MAPBOX_VERBOSE' in os.environ:
        click.echo("MAPBOX_VERBOSE = {0}".format(
            os.environ['MAPBOX_VERBOSE']))
    click.echo("")

    if 'config_file' in ctx.obj:
        click.echo("Config file {0}:".format(ctx.obj['config_file']))
        for key, value in ctx.default_map.items():
            click.echo("{0} = {1}".format(key, value))
        click.echo("")