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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'  },  {    name: 'mary',    age: 30,    birthday: new Date().setFullYear((new Date().getFullYear() - 30)),    gender: 'Female'  },  {    name: 'bob',    age: 21,    birthday: new Date().setFullYear((new Date().getFullYear() - 21)),    gender: 'Male'  },  {    name: 'lilly',    age: 26,    birthday: new Date().setFullYear((new Date().getFullYear() - 26)),    gender: 'Female'  },  {    name: 'alucard',    age: 1000,    birthday: new Date().setFullYear((new Date().getFullYear() - 1000)),    gender: 'Male'  }];

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    }
    // alright, simple map reduce example. We will find the total ages of each    // gender
    // create the options object    const o = {};
    o.map = function() {      // in this function, 'this' refers to the current document being      // processed. Return the (gender, age) tuple using      /* global emit */      emit(this.gender, this.age);    };
    // the reduce function receives the array of ages that are grouped by the    // id, which in this case is the gender    o.reduce = function(id, ages) {      return Array.sum(ages);    };
    // other options that can be specified
    // o.query = { age : { $lt : 1000 }}; // the query object    // o.limit = 3; // max number of documents    // o.keeptemp = true; // default is false, specifies whether to keep temp data    // o.finalize = someFunc; // function called after reduce    // o.scope = {}; // the scope variable exposed to map/reduce/finalize    // o.jsMode = true; // default is false, force execution to stay in JS    o.verbose = true; // default is false, provide stats on the job    // o.out = {}; // objects to specify where output goes, by default is    // returned, but can also be stored in a new collection    // see: http://mongoosejs.com/docs/api.html#model_Model-mapReduce    Person.mapReduce(o, function(err, results, stats) {      console.log('map reduce took %d ms', stats.processtime);      console.log(results);      cleanup();    });  });});
function cleanup() {  Person.remove(function() {    mongoose.disconnect();  });}