Week 4 Volume

I'm naturally a suspicious person, so forgive me if this is obvious. It seems that they have essentially provided the answer for both todos in week 4 Volume. Is this problem a scaffold for the next problem? Did they just realize how difficult the problem was and wanted to provide the answer, so people just didn't google it? I assume they are hoping we understand the code before we use their example code? Next time, I will attempt first before reading the hints. Probably thinking about this too much.