def window(*args, &blk)
      win = Window.new self, extract_selector(args)

      win.use(&blk) if block_given?

      win
    end
def window(*args, &blk)
      win = Window.new self, extract_selector(args)

      win.use(&blk) if block_given?

      win
    end
Returns browser window.

 @example
   browser.window(title: 'closeable window')

 @return [Window]