                 oldController.view.removeFromSuperview()
                 oldController.removeFromParentViewController()
             }
+
             guard let drawerViewController = drawerViewController else { return }
-            let viewDictionary      = ["drawerView" : drawerViewController.view]
+            addChildViewController(drawerViewController)
+
+            drawerViewController.view.layer.shadowColor   = UIColor.blackColor().CGColor
+            drawerViewController.view.layer.shadowOpacity = 0.4
+            drawerViewController.view.layer.shadowRadius  = 5.0
+            drawerViewController.view.translatesAutoresizingMaskIntoConstraints = false
+            _containerView.addSubview(drawerViewController.view)
+
             let itemAttribute: NSLayoutAttribute
             let toItemAttribute: NSLayoutAttribute
             switch drawerDirection {

                    views: viewDictionary
                )
            )
            mainViewController.didMoveToParentViewController(self)
        }
    }

                itemAttribute   = .Left
                toItemAttribute = .Right
            }

            _drawerWidthConstraint = NSLayoutConstraint(
                item: drawerViewController.view,
                attribute: NSLayoutAttribute.Width,
