js/libs/ember-data.js
function(key) {
    var factory;


    if (typeof key === 'string') {
      var normalizedKey = this.container.normalize('model:' + key);

      factory = this.container.lookupFactory(normalizedKey);
      if (!factory) { throw new Ember.Error("No model was found for '" + key + "'"); }
      factory.typeKey = normalizedKey.split(':', 2)[1];
    } else {
      // A factory already supplied.
      factory = key;
    }

    factory.store = this;
    return factory;
  }
function(key) {
    var factory;


    if (typeof key === 'string') {
      var normalizedKey = this.container.normalize('model:' + key);

      factory = this.container.lookupFactory(normalizedKey);
      if (!factory) { throw new Ember.Error("No model was found for '" + key + "'"); }
      factory.typeKey = normalizedKey.split(':', 2)[1];
    } else {
      // A factory already supplied.
      factory = key;
    }

    factory.store = this;
    return factory;
  }
Returns a model class for a particular key. Used by
methods that take a type key (like `find`, `createRecord`,
etc.)

@method modelFor
@param {String or subclass of DS.Model} key
@returns {subclass of DS.Model}