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// import async to make control flow simplier'use strict';
const async = require('async');
// import the rest of the normal stuffconst mongoose = require('../../lib');
require('./person.js')();
const Person = mongoose.model('Person');
// define some dummy dataconst data = [  {    name: 'bill',    age: 25,    birthday: new Date().setFullYear((new Date().getFullYear() - 25)),    gender: 'Male',    likes: ['movies', 'games', 'dogs']  },  {    name: 'mary',    age: 30,    birthday: new Date().setFullYear((new Date().getFullYear() - 30)),    gender: 'Female',    likes: ['movies', 'birds', 'cats']  },  {    name: 'bob',    age: 21,    birthday: new Date().setFullYear((new Date().getFullYear() - 21)),    gender: 'Male',    likes: ['tv', 'games', 'rabbits']  },  {    name: 'lilly',    age: 26,    birthday: new Date().setFullYear((new Date().getFullYear() - 26)),    gender: 'Female',    likes: ['books', 'cats', 'dogs']  },  {    name: 'alucard',    age: 1000,    birthday: new Date().setFullYear((new Date().getFullYear() - 1000)),    gender: 'Male',    likes: ['glasses', 'wine', 'the night']  }];

mongoose.connect('mongodb://localhost/persons', function(err) {  if (err) throw err;
  // create all of the dummy people  async.each(data, function(item, cb) {    Person.create(item, cb);  }, function(err) {    if (err) {      // handle error    }
    // run an aggregate query that will get all of the people who like a given    // item. To see the full documentation on ways to use the aggregate    // framework, see http://docs.mongodb.org/manual/core/aggregation/    Person.aggregate(      // select the fields we want to deal with      { $project: { name: 1, likes: 1 } },      // unwind 'likes', which will create a document for each like      { $unwind: '$likes' },      // group everything by the like and then add each name with that like to      // the set for the like      { $group: {        _id: { likes: '$likes' },        likers: { $addToSet: '$name' }      } },      function(err, result) {        if (err) throw err;        console.log(result);        /* [         { _id: { likes: 'the night' }, likers: [ 'alucard' ] },         { _id: { likes: 'wine' }, likers: [ 'alucard' ] },         { _id: { likes: 'books' }, likers: [ 'lilly' ] },         { _id: { likes: 'glasses' }, likers: [ 'alucard' ] },         { _id: { likes: 'birds' }, likers: [ 'mary' ] },         { _id: { likes: 'rabbits' }, likers: [ 'bob' ] },         { _id: { likes: 'cats' }, likers: [ 'lilly', 'mary' ] },         { _id: { likes: 'dogs' }, likers: [ 'lilly', 'bill' ] },         { _id: { likes: 'tv' }, likers: [ 'bob' ] },         { _id: { likes: 'games' }, likers: [ 'bob', 'bill' ] },         { _id: { likes: 'movies' }, likers: [ 'mary', 'bill' ] }         ] */
        cleanup();      });  });});
function cleanup() {  Person.remove(function() {    mongoose.disconnect();  });}