title: Class implementing UITableViewDataSource is always null
body: <p>I have a tableview that should have its delegate and datasource properties set from <code>InsertIntoTableViewDelegate</code> and <code>InsertIntoTableViewDatasource</code> Classes respectively. However, my <code>InsertIntoTableViewDatasource</code> class always returns <code>null</code>. </p>
  
  <p>Here is the code:</p>
  
  <pre><code>class InsertIntoTableViewDatasource: NSObject,UITableViewDataSource {
  
      var data:NSMutableArray
  
      init(With data: NSMutableArray){
          self.data = data
      }
  
  
      func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -&gt; Int {
          return data.count
      }
  
      func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -&gt; UITableViewCell {
          let cell = tableView.dequeueReusableCellWithIdentifier("rowCell", forIndexPath: indexPath)
          cell.textLabel?.text = data[indexPath.row] as? String
          return cell
      }
  }
  </code></pre>
  
  <p>Here is the how the tableview is being set:</p>
  
  <pre><code>override func viewDidLoad() {
      super.viewDidLoad()
      self.title = "Testing"
      tableView.dataSource = InsertIntoTableViewDatasource(With: data)
      tableView.delegate = InsertIntoTableViewDelegate()
  }
  </code></pre>
  
  <p><strong>Why is this the case?</strong></p>