code: def _get_restore_function(self):
          
          if os.name == 'nt' or not self.getch_enabled:
              return lambda signal, frame: None
  
          try:
              fd = self.stdin.fileno()
              initial = termios.tcgetattr(fd)
          except termios.error:
              return lambda signal, frame: None
  
          return lambda signal, frame: termios.tcsetattr(fd, termios.TCSADRAIN, initial)
docs: Return the binary function for restoring terminal attributes.
          :return: function (signal, frame) => None: