code: def test_add_asset_multiple_times_ignored():
      scene = Scene()
      view1 = mock.Mock(view.View)
      scene.link_view(view1)
      asset = assets.Asset()
  
      # call three times
      scene.add(asset)
      scene.add(asset)
      scene.add(asset)
  
      # but make sure it is only added once
      assert scene.assets == (asset,)
      assert asset.scenes == [scene]
      view1.add.assert_called_once_with(asset)
  
file_path: kubric/test/test_scene.py
imports: from unittest import mock
  from kubric.core.scene import Scene
  from kubric.core.cameras import PerspectiveCamera
  from kubric.core import assets
  from kubric.core import objects
  from kubric.core import materials
  from kubric.core import view
  from kubric.core.color import get_color
label_desc: Use image node_id 5 for calling a global function with example usage: test_add_asset_multiple_times_ignored() without return types