code: def test_save_restore_plugin_config(self):
      viewer = PerspectiveViewer(
          plugin="Datagrid",
          plugin_config={"columns": {"a": {"fixed": 4}}},
      )
      config = viewer.save()
  
      assert config["plugin_config"] == {"columns": {"a": {"fixed": 4}}}
  
      viewer.reset()
      assert viewer.plugin_config == {}
  
      viewer.restore(**config)
      assert viewer.plugin_config == config["plugin_config"]
  
imports: import numpy
  import pandas
  from perspective import PerspectiveViewer, Table
label_desc: Use image node_id 24 for calling the TestViewer obj's underlying member method code with example usage: obj.test_save_restore_plugin_config() without return types