def __init__(self, assets_dir=None, requirements_file="requirements.yml"):
        self.assets_dir = assets_dir or Path(".") / "assets"
        self.requirements = GroupedRequirements()
        self.requirements.load(requirements_file)
        self.temp_dir = mkdtemp()
def encode(self):
        return {"rx_sw_if_index": self._rx_index,
                "tx_sw_if_index": self._tx_index, "nh": self._nh_addr}