+ ///
+ /// let relative_path = Path::new("foo/bar");
+ /// let parent = relative_path.parent();
+ /// assert_eq!(parent, Some(Path::new("foo")));
+ /// let grand_parent = parent.and_then(Path::parent);
+ /// assert_eq!(grand_parent, Some(Path::new("")));
+ /// let great_grand_parent = grand_parent.and_then(Path::parent);
+ /// assert_eq!(great_grand_parent, None);