unimplemented!()
}
-// **Exercise 10.1**: Look up the [documentation of `Iterator`](http://doc.rust-lang.org/stable/std/iter/trait.Iterator.html) to learn about more functions
+// **Exercise 10.1**: Look up the [documentation of `Iterator`](https://doc.rust-lang.org/stable/std/iter/trait.Iterator.html) to learn about more functions
// that can act on iterators. Try using some of them. What about a function that sums the even numbers of an iterator? Or a function that computes the
// product of those numbers that sit at odd positions? A function that checks whether a vector contains a certain number? Whether all numbers are
// smaller than some threshold? Be creative!