In this section, you're going to learn how to improve your Mongoose models. This is going to let you add things like validation. You can make certain properties be a requirement, and you can set up smart defaults. So, if something like completed is not provided, you can have a default value that gets set. All of this functionality is built into Mongoose; we just have to learn how to use it.
To illustrate why we'd want to set this stuff up, let's scroll to the bottom of our server file and remove all of the properties on the new Todo we created. Then, we're going to save the file and move into the Terminal, running the script. That's going to be node in the server directory, and the file is going to be called ...