def METHOD_NAME(elem):
    points = []
    for vertex in elem.findall("Vertex"):
        points.append((
            float(vertex.findtext("FRAME_LON")),
            float(vertex.findtext("FRAME_LAT"))
        ))
    if points[0] != points[-1]:
        points.append(points[0])
    return MultiPolygon(Polygon(points))