code: def start(self):
      display(self)
      self._update_data()
      while not self._need_to_stop.wait(1.0):
          self._update_data()
  
      if self._update_after_stop_signal:
          self._update_data()
  
file_path: catboost/catboost/python-package/catboost/widget/ipythonwidget.py
imports: import os
  import json
  from threading import Thread, Event
  from traitlets import Unicode, Dict, default
  from IPython.display import display
  from ipywidgets import DOMWidget, Layout, widget_serialization
label_desc: Use image node_id 2 for calling the MetricVisualizer obj's underlying member method code with example usage: obj.start() without return types