   override func collectionView(_ collectionView: UICollectionView,
                                cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
     let cell =
-        collectionView.dequeueReusableCell(withReuseIdentifier: "MDCCatalogCollectionViewCell",
-                                           for: indexPath)
+      collectionView.dequeueReusableCell(withReuseIdentifier: "MDCCatalogCollectionViewCell",
+                                         for: indexPath)
     cell.backgroundColor = AppTheme.containerScheme.colorScheme.backgroundColor
 
     let componentName = node.children[indexPath.row].title

    return node.children.count
  }

  func inkViewForView(_ view: UIView) -> MDCInkView {
    let foundInkView = MDCInkView.injectedInkView(for: view)
    foundInkView.inkStyle = .bounded
    foundInkView.inkColor = UIColor(white:0.957, alpha: 0.2)
    return foundInkView
  }

  // MARK: MDCInkTouchControllerDelegate

  func inkTouchController(_ inkTouchController: MDCInkTouchController,
                          shouldProcessInkTouchesAtTouchLocation location: CGPoint) -> Bool {
    return self.collectionView!.indexPathForItem(at: location) != nil
  }

  func inkTouchController(_ inkTouchController: MDCInkTouchController,
                          inkViewAtTouchLocation location: CGPoint) -> MDCInkView? {
    if let indexPath = self.collectionView!.indexPathForItem(at: location) {
      let cell = self.collectionView!.cellForItem(at: indexPath)
      return inkViewForView(cell!)
    }
    return MDCInkView()
  }

  // MARK: UICollectionViewDelegate

  override func viewDidLoad() {
    super.viewDidLoad()

    rippleController.addRipple(to: self.collectionView!)

    let containerView = UIView(frame: headerViewController.headerView.bounds)
    containerView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
