// **Exercise 07.1**: Add some more testcases. In particular, make sure you test the behavior of
// `vec_min` on an empty vector. Also add tests for `BigInt::from_vec` (in particular, removing
// trailing zeros). Finally, break one of your functions in a subtle way and watch the test fail.
// **Exercise 07.1**: Add some more testcases. In particular, make sure you test the behavior of
// `vec_min` on an empty vector. Also add tests for `BigInt::from_vec` (in particular, removing
// trailing zeros). Finally, break one of your functions in a subtle way and watch the test fail.