def METHOD_NAME(self, source, dest):
    "Simplify a TopoJSON file"
    # The toposimplify settings here were arrived at by trial and error to keep the
    # simplified 2018-05-03 local elections topojson below 2.5MB.
    subprocess.check_call(
        [
            os.path.join(TOPOJSON_BIN, "toposimplify"),
            "-S",
            "0.2",
            "-F",
            "-o",
            dest,
            source,
        ]
    )