title: what does createContainer in Meteor using React do?
body: <p>I'm working on the Meteor using React tutorial and trying to understand createContainer().  From reading here:</p>
  
  <p><a href="http://guide.meteor.com/v1.3/react.html#using-createContainer">http://guide.meteor.com/v1.3/react.html#using-createContainer</a> </p>
  
  <p>I think that its a function defined in <code>meteor/react-meteor-data</code> that is used for data loading. In this specific case, it retrieving data from the Mini Mongo Database (named <code>Task</code> here).  My question is, what does the second argument to createContainer do?  (named <code>App</code> here).  Thank you!</p>
  
  <pre><code>class App extends Component {
     //...class definition
  }
  
   export default createContainer(() =&gt; {
    return {
      //Tasks is a Mongo.Collection
      //returns the matching rows (documents)
      //here we define the value for tasks member
      tasks: Tasks.find({}, { sort: { createdAt: -1} }).fetch(),
    };
  }, App);
  </code></pre>