code: def format_close(code: int, reason: str) -> str:
      
      if 3000 <= code < 4000:
          explanation = "registered"
      elif 4000 <= code < 5000:
          explanation = "private use"
      else:
          explanation = CLOSE_CODES.get(code, "unknown")
      result = f"code = {code} ({explanation}), "
  
      if reason:
          result += f"reason = {reason}"
      else:
          result += "no reason"
  
      return result
docs: Display a human-readable version of the close code and reason.