code: def setUp(self):
      super().setUp()
      if not notebook_extension._loaded:
          notebook_extension("matplotlib", ip=self.ip)
      self.backup = Store.display_formats
      Store.display_formats = self.format
  
imports: from holoviews import Curve, Store
  from holoviews.ipython import IPTestCase, notebook_extension
label_desc: Use image node_id 1 for calling the TestDisplayHooks obj's underlying member method code with example usage: obj.setUp() without return types