text: var mongoose = require('mongoose'),
      Customer = mongoose.model('Customer'),
      Address = mongoose.model('Address'),
      Billing = mongoose.model('Billing');
  exports.getCustomer = function(req, res) {
    Customer.findOne({ userid: 'customerA' })
    .exec(function(err, customer) {
      if (!customer){
        res.json(404, {msg: 'Customer Not Found.'});
      } else {
        res.json(customer);
      }
    });
  };
  exports.updateShipping = function(req, res){
    var newShipping = new Address(req.body.updatedShipping);
    Customer.update({ userid: 'customerA' },
        {$set:{shipping:[newShipping.toObject()]}})
    .exec(function(err, results){
      if (err || results < 1){
       res.json(404, {msg: 'Failed to update Shipping.'});
      } else {
       res.json({msg: "Customer Shipping Updated"});
      }
    });
  };
  exports.updateBilling = function(req, res){
    // This is where you could verify the credit card information
    // and halt the checkout if it is invalid.
    var newBilling = new Billing(req.body.updatedBilling);
    Customer.update({ userid: 'customerA' },
        {$set:{billing:[newBilling.toObject()]}})
    .exec(function(err, results){
      if (err || results < 1){
       res.json(404, {msg: 'Failed to update Billing.'});
      } else {
       res.json({msg: "Customer Billing Updated"});
      }
    });
  };
  exports.updateCart = function(req, res){
    Customer.update({ userid: 'customerA' },
        {$set:{cart:req.body.updatedCart}})
    .exec(function(err, results){
      if (err || results < 1){
       res.json(404, {msg: 'Failed to update Cart.'});
      } else {
       res.json({msg: "Customer Cart Updated"});
      }
    });
  };
  