How to dismiss MWPhotoBrowser while presenting modally?

I'm using an MWPhotoBrowser instance to show albums or single images in my app. While using a navigation controller, I can simply press the back button to pop the view controller. I wish to present it modally but I can't figure out how to dismiss it. I tried the following code in the hopes that I would be able to swipe down to dismiss, but to no avail.

    let browser = MWPhotoBrowser(photos: photos)
    browser?.delegate = self
    browser?.enableSwipeToDismiss
    self.present(browser!, animated: true, completion: nil)

(photos is an array of MWPhoto)

Can anyone point me to a solution? Thanks.

Considering that you can't edit MWPhotoBrowser. You can approach this problem by adding a floating button after

let windowButton: UIButton = UIButton(type: UIButtonType.custom)
let browser:MWPhotoBrowser? // declared outside functions

self.present(browser, animated: true, completion: {
      self.windowButton.frame = CGRect(x: 20, y: 100, width: 50, height: 50)
      self.windowButton.backgroundColor = UIColor.brown
      self.windowButton.addTarget(self, action: #selector(self.dismissFunc), for: UIControlEvents.touchDown)
      if let window:UIWindow = (UIApplication.shared.delegate?.window)! {
          window.addSubview(self.windowButton)
      }
 })

func dismissFunc() {
    self.browser.dismiss(animated: true, completion: {
        self.windowButton.removeFromSuperview()
    })
}