code: def keyPressEvent(self, event):
          
          if event.key() == QtCore.Qt.Key_Escape:
              self.cancel()
          elif event.key() == QtCore.Qt.Key_Left:
              self.goBack()
          elif event.key() == QtCore.Qt.Key_Right:
              self.goForward()
          elif event.key() == QtCore.Qt.Key_Home:
              self.restart()
          
          super(XWalkthroughWidget, self).keyPressEvent(event)
docs: Listens for the left/right keys and the escape key to control
          the slides.
          
          :param      event | <QtCore.Qt.QKeyEvent>