title: displaying front viewcontroller of SWReveal with toggle botton
body: <p>I have an application where I am using SWreveal and I also have a bottomSheet in the front View controller. I have to open the view controller programmatically for the bottom sheet to work and the issue I have now is if I have a code like this </p>
  
  <pre><code>let storyboard = R.storyboard.baseSB()
  
              let swVC = storyboard.instantiateViewController(withIdentifier: SWRevealViewController.className) as! SWRevealViewController
  
              swVC.loadView()
  
              let homeVC = swVC.frontViewController as! HomeVC
  
              homeVC.mode = AppMode.go
              let bottomSheetVC = BottomSheetVC(contentViewController: swVC, drawerViewController: UIViewController())
              bottomSheetVC.drawerCornerRadius = 0
              bottomSheetVC.initialDrawerPosition = .closed
              bottomSheetVC.shadowRadius = 0
              bottomSheetVC.shadowOpacity = 0
  
              homeVC.bottomDrawer = bottomSheetVC
              bottomSheetVC.modalTransitionStyle = .crossDissolve
  
              self?.present(bottomSheetVC, animated: true, completion: nil)
  </code></pre>
  
  <p>everything works with the side drawer and i can toggle the view controllers but the bottomSheet does not work, passing it in like this, makes the bottoSheet work but if I click on the toggle button the app crashes</p>
  
  <pre><code>let storyboard = R.storyboard.baseSB()
  
  let swVC = storyboard.instantiateViewController(withIdentifier: SWRevealViewController.className) as! SWRevealViewController
  
  swVC.loadView()
  storyboard.instantiateViewController(withIdentifier: HomeVC.className) as! HomeVC
  
  let homeVC = swVC.frontViewController as! HomeVC
  
  homeVC.mode = AppMode.go
  let bottomSheetVC = BottomSheetVC(contentViewController: homeVC, drawerViewController: UIViewController())
  bottomSheetVC.drawerCornerRadius = 0
  bottomSheetVC.initialDrawerPosition = .closed
  bottomSheetVC.shadowRadius = 0
  bottomSheetVC.shadowOpacity = 0
  
  homeVC.bottomDrawer = bottomSheetVC
  bottomSheetVC.modalTransitionStyle = .crossDissolve
  
  self?.present(bottomSheetVC, animated: true, completion: nil)
  </code></pre>
  
  <p>how can I fix this so that the application works without a crash when I toggle the side view controller button</p>