def minimum_bounding_box(geojson):
    """Gets the minimum bounding box for a geojson polygon.

    Args:
        geojson (dict): A geojson dictionary.

    Returns:
        tuple: Returns a tuple containing the minimum bounding box in the format of (lower_left(lat, lon), upper_right(lat, lon)), such as ((13, -130), (32, -120)).
    """
    coordinates = []
    try:
        if 'geometry' in geojson.keys():
            coordinates = geojson['geometry']['coordinates'][0]
        else:
            coordinates = geojson['coordinates'][0]

        lower_left = min([x[1] for x in coordinates]), min(
            [x[0] for x in coordinates])  # (lat, lon)
        upper_right = max([x[1] for x in coordinates]), max([x[0]
                                                             for x in coordinates])  # (lat, lon)
        bounds = (lower_left, upper_right)
        return bounds
    except Exception as e:
        # print(e)
        return None