old_contents: var app = require('express')();
  
  app.get('/', function(req, res) {
    res.send('Hello World!');
  });
  
  var server = app.listen(3000, function() {
    console.log('Listening on http://localhost:3000');
  });
  
new_contents: var app = require('express')();
  var db = require('mongoose');
  db.connect('mongodb://localhost/caedence_net_development');
  
  var Note = db.model('Note', {
    title: String,
    body_html: String,
    body_text: String,
    user_id: Number,
    created_at: { type: Date, default: Date.now },
    updated_at: { type: Date, default: Date.now }
  });
  
  // create some records with mongo cli like this:
  // $ mongod
  // > use caedence_net_development
  // > db.notes.insert({ title: "Hello", body_html: "<p>World</p>", body_text: "World" })
  // WriteResult({ "nInserted" : 1 })
  // > db.notes.find()
  // { "_id" : ObjectId("562473c0802fa33ca991217b"), "title" : "Hello", "body_html" : "<p>World</p>", "body_text" : "World" }
  app.get('/notes/', function(req, res) {
    Note.find(function(err, notes) {
      res.json(notes);
    });
  });
  app.get('/', function(req, res) {
    res.send('Hello World!');
  });
  
  var server = app.listen(3000, function() {
    console.log('Listening on http://localhost:3000');
  });
  
subject: Create Mongoose model for Note, and list notes.