title: IGListKit with sections and multiple items
body: <p>I'm trying to implement a collection view with IGListKit. It can either have one or three sections. The datasource is populated in realtime and so needs to refresh the content when new data are available.</p>
  
  <p>To do so, I've created a datasource object conform to <code>IGListDiffable</code> that represent each section as such:</p>
  
  
  
  <pre class="lang-c prettyprint-override"><code>final class DataSource: NSObject {
    var title: String?
    var items: [SJResult] = []
  }
  
  extension DataSource: IGListDiffable {
    public func diffIdentifier() -&gt; NSObjectProtocol {
      return self
    }
  
    public func isEqual(toDiffableObject object: IGListDiffable?) -&gt; Bool {
      if object === self {
        return true
      }
      guard let obj = object as? DataSource else {
        return false
      }
      return obj.items.count == items.count
    }
  }
  </code></pre>
  
  <p>Inside each section, I would like to display a list of <code>items</code>. I've managed to create the section by reusing the same section controller, but the only way I've found to insert new result was to do call <code>reloadData()</code> on the adapter. This is pretty bad as it will reload the complete list of items (which can potentially be very long, >50 items). It also give no possibility to animate the insertion of new item. I've also tried to do a <code>adapter.performUpdates(animated: true)</code> with no luck as it only refresh my datasource but not the items inside the datasource.</p>
  
  <p>I then tried to create a section controller which will display each section with one cell. The cell would contain a <code>IGListCollectionView</code> and will take care of display the <code>items</code>, but with this I had no luck as well as despite the second section controller receives the objects it never displays the cells.</p>
  
  <p>I'm a bit struggling now and not sure how I could display three different section that use the same type of cells with IGListKit, by having the sections static and the items dynamic. I'm thinking of creating three <code>IGListCollectionView</code> and setup bottom / top constraints between them, but I'm having some doubt on the possibility of doing that.</p>
  
  <p>I'm wondering if someone already came across a similar issue and/or if the guys from IGListKit could give me some hints of what's the best implementation to resolve that?</p>