def METHOD_NAME(self, group: VehicleGroup, convoy: Convoy) -> None:
    for unit, unit_type in zip(group.units, convoy.iter_units()):
        # The actual name is a String (the pydcs translatable string), which
        # doesn't define __eq__.
        name = str(unit.name)
        if name in self.convoys:
            raise RuntimeError(f"Duplicate convoy unit: {name}")
        self.convoys[name] = ConvoyUnit(unit_type, convoy)