code: def display_center(text, width, fillchar=' '):
      
      if character_width(fillchar) != 1:
          raise ValueError("The padding character must have display width 1")
  
      text_width = monospaced_width(text)
      if text_width == -1:
          return text
  
      padding = max(0, width - text_width)
      left_padding = padding // 2
      right_padding = padding - left_padding
      return fillchar * left_padding + text + fillchar * right_padding
docs: Return `text` centered in a Unicode string whose display width, in a
      monospaced terminal, should be at least `width` character cells. The rest
      of the string will be padded with `fillchar`, which must be a width-1
      character.
  
      >>> lines = ['Table flip', '(╯°□°)╯︵ ┻━┻', 'ちゃぶ台返し']
      >>> for line in lines:
      ...     print(display_center(line, 20, '▒'))
      ▒▒▒▒▒Table flip▒▒▒▒▒
      ▒▒▒(╯°□°)╯︵ ┻━┻▒▒▒▒
      ▒▒▒▒ちゃぶ台返し▒▒▒▒