code: def _user_input() -> str:
      
  
      lines = []
      try:
          while True:
              line = input()
              if line != '':
                  lines.append(line)
              else:
                  break
      except (EOFError, KeyboardInterrupt):
          return '\n'.join(lines)
docs: A helper function which waits for user multi-line input.
  
      :return: A string input by user, separated by ``'\\n'``.