def METHOD_NAME(self) -> None:
    fx = self.fx
    assert set(
        infer_constraints(
            Instance(
                fx.gv2i,
                [
                    fx.u,
                    UnpackType(
                        TupleType([fx.t, fx.s], fallback=Instance(fx.std_tuplei, [fx.o]))
                    ),
                    fx.u,
                ],
            ),
            Instance(fx.gv2i, [fx.a, fx.b, fx.d]),
            SUPERTYPE_OF,
        )
        # We still get constraints on the prefix/suffix in this case.
    ) == {
        Constraint(type_var=fx.u, op=SUPERTYPE_OF, target=fx.a),
        Constraint(type_var=fx.u, op=SUPERTYPE_OF, target=fx.d),
    }