text: var mongoose = require('mongoose');
  var Schema = mongoose.Schema;
  var ObjectId = Schema.Types.ObjectId;
  var deepPopulate = require('mongoose-deep-populate')(mongoose);
  var uniqueValidator = require('mongoose-unique-validator');
  mongoose.Promise = require('bluebird');
  // setup plugins
  mongoose.plugin(uniqueValidator);
  mongoose.plugin(deepPopulate);
  
  module.exports.User = mongoose.model('User', require('./userSchema'));
  module.exports.StudySet = mongoose.model('StudySet', require('./studySetSchema'));