code: def update(self, msg: str, add_sleep: float | None = None):
      self.lines.append(msg)
      self._panel.update(Panel("\n".join(self.lines)))
      if add_sleep:
          time.sleep(add_sleep)
  
file_path: gradio/gradio/cli/commands/display.py
imports: from __future__ import annotations
  import time
  from types import TracebackType
  from typing import Optional
  from rich.live import Live
  from rich.panel import Panel
label_desc: Use image node_id 2 for calling the LivePanelDisplay obj's underlying member method code with example usage: obj.update(msg, add_sleep) without return types