old_contents: 
  var assert = require('assert')
  var slice = require('sliced')
  var mongo = require('mongodb')
  var utils = require('../../').utils;
  var client = require('redis').createClient(process.env.REDIS_URL);
  
  var uri = process.env.MQUERY_URI || 'mongodb://localhost/mquery';
  var db;
  
  exports.getCollection = function (cb) {
    mongo.Db.connect(uri, function (err, db_) {
      assert.ifError(err);
      db = db_;
  
      var collection = db.collection('stuff');
      collection.opts.safe = true;
  
      // clean test db before starting
      db.dropDatabase(function () {
        cb(null, collection);
      });
    })
  }
  
  exports.dropCollection = function (cb) {
    db.dropDatabase(function () {
      db.close(cb);
    })
  }
  
new_contents: 
  var assert = require('assert')
  var slice = require('sliced')
  var mongo = require('mongodb')
  var utils = require('../../').utils;
  
  var uri = process.env.MQUERY_URI || 'mongodb://localhost/mquery';
  var db;
  
  exports.getCollection = function (cb) {
    mongo.Db.connect(uri, function (err, db_) {
      assert.ifError(err);
      db = db_;
  
      var collection = db.collection('stuff');
      collection.opts.safe = true;
  
      // clean test db before starting
      db.dropDatabase(function () {
        cb(null, collection);
      });
    })
  }
  
  exports.dropCollection = function (cb) {
    db.dropDatabase(function () {
      db.close(cb);
    })
  }
  
subject: Update node.js