// shortest way: mongoose will be loaded by mongoose-q
var mongoose = require('co-mongoose')();

SomeModel.findByIdQ(....blahblah...)
  .then(function (result) { ... })
  .fail(function (err) { ... })
  .done();

var someModel = new SomeModel(...);
someModel.populateQ()
  .then(function (result) { ... })
  .fail(function (err) { ... })
  .done();

SomeModel.find(...).where(...).skip(...).limit(...).sort(...).populate(...)
  .execQ() // no 'Q' suffix for model statics except for execQ()
  .then(function (result) { ... })
  .fail(function (err) { ... })
  .done();

var mongoose = require('mongoose-q')(require('mongoose'), {prefix:'promiseOf_', suffix:'_withQ'});
SomeModel.promiseOf_findAndUpdate_withQ(...)
  .then(function (result) { ... })
  .fail(function (err) { ... })
  .done();

function customMapper(name) {
  return 'q' + name.charAt(0).toUpperCase() + name.substring(1);
}
var mongoose = require('mongoose-q')(require('mongoose'), {mapper:customMapper});
SomeModel.qFindAndUpdate(...)
  .then(function (result) { ... })
  .fail(function (err) { ... })
  .done();

var mongoose = require('mongoose-q')(require('mongoose'), {spread:true});
SomeModel.updateQ(...)
  .spread(function (affectedRows, raw) { ... })
  .fail(function (err) { ... })
  .done();
SomeModel.updateQ(...)
  .then(function (result) { var affectedRows = result[0], raw = result[1]; ... })
  .fail(function (err) { ... })
  .done();
...
var model = new SomeModel();
...
model.saveQ()
  .spread(function (savedDoc, affectedRows) { ... })
  .fail(function (err) { ... })
  .done();
...
model.saveQ()
  .then(function (result) { var savedDoc = result[0], affectedRows = result[1]; ... })
  .fail(function (err) { ... })
  .done();

SomeSchema.statics.findByName = function (name) {
  return this.findQ({name: name}); // NOTE: returns Promise object.
};
...
var SomeModel = mongoose.model('Some', SomeSchema);
SomeModel.findByName('foo').then(function(result) {
  console.log(result);
});